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LIGO/Virgo S200213t

GCN Circular 27041

Subject
LIGO/Virgo S200213t: Global MASTER-Net observations report
Date
2020-02-13T04:33:04Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev, O.Ershova 
(Irkutsk State University, API),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich, Yu. Sergienko 
(Blagoveschensk Educational State University)




MASTER-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) started inspect of the LIGO/Virgo S200213t errorbox  113 sec after notice time and 397 sec after trigger time at 2020-02-13 04:17:17 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 79 deg. The sun  altitude  is -45.8 deg. 

The galactic latitude b = -7 deg., longitude l = 126 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11324

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     488 | 2020-02-13 04:17:17 |          MASTER-IAC | (20h 29m 19.75s , +57d 55m 31.9s) |   C |   180 | 17.5 |        
     488 | 2020-02-13 04:17:17 |          MASTER-IAC | (20h 44m 39.60s , +57d 50m 46.6s) |   C |   180 | 17.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.

GCN Circular 27042

Subject
LIGO/Virgo S200213t: Identification of a GW compact binary merger candidate
Date
2020-02-13T04:36:05Z (5 years ago)
From
Leo Singer at GSFC <leo.p.singer@nasa.gov>
The LIGO Scientific Collaboration and the Virgo Collaboration report:

We identified the compact binary merger candidate S200213t during
real-time processing of data from LIGO Hanford Observatory (H1), LIGO
Livingston Observatory (L1), and Virgo Observatory (V1) at 2020-02-13
04:10:40.328 UTC (GPS time: 1265602258.328). The candidate was found
by the GstLAL [1] analysis pipeline.

S200213t is an event of interest because its false alarm rate, as
estimated by the online analysis, is 1.8e-08 Hz, or about one in 1
year, 9 months. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S200213t

The classification of the GW signal, in order of descending
probability, is BNS (63%), Terrestrial (37%), BBH (<1%), MassGap
(<1%), or NSBH (<1%).

Assuming the candidate is astrophysical in origin, the probability
that the lighter compact object has a mass < 3 solar masses (HasNS) is
>99%. Using the masses and spins inferred from the signal, the
probability of matter outside the final compact object (HasRemnant) is
>99%.

Two sky maps are available at this time and can be retrieved from the
GraceDB event page:
 * bayestar.fits.gz,0, an initial localization generated by BAYESTAR
[2], distributed via GCN notice about 2 minutes after the candidate
event time.
 * bayestar.fits.gz,1, an initial localization generated by BAYESTAR
[2], distributed via GCN notice about 7 minutes after the candidate
event time.

The preferred sky map at this time is bayestar.fits.gz,1. For the
bayestar.fits.gz,1 sky map, the 90% credible region is 2587 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 224 +/- 90 Mpc (a posteriori mean +/- standard deviation).

For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.

 [1] Messick et al. PRD 95, 042001 (2017)
 [2] Singer & Price PRD 93, 024013 (2016)

GCN Circular 27043

Subject
LIGO/Virgo S200213t: 1 counterpart neutrino candidate from IceCube neutrino searches
Date
2020-02-13T04:40:26Z (5 years ago)
From
Raamis Hussain at IceCube <raamis.hussain@icecube.wisc.edu>
IceCube Collaboration (http://icecube.wisc.edu/) reports:

Searches for track-like muon neutrino events detected by IceCube consistent
with the sky
localization of gravitational-wave candidate S200213t in a time range of
1000 seconds [1]
centered on the alert event time (2020-02-13 04:02:20.328 UTC to 2020-02-13
04:19:00.328 UTC) have been performed.
During this time period IceCube was collecting good quality data. Two
hypothesis tests
were conducted. The first search is a maximum likelihood analysis which
searches for a
generic point-like neutrino source coincident with the given GW skymap [2].
The
second uses a Bayesian approach to quantify the joint GW + neutrino event
significance, which
assumes a binary merger scenario and accounts for known astrophysical
priors in the
significance estimate, such as GW source distance [3].

1 track-like event is found in spatial and temporal coincidence with the
gravitational-wave
candidate S200213t calculated from the map circulated in the 3-Initial
notice. This
represents an overall p-value of 0.003 (2.75sigma) from the generic
transient search
and an overall p-value of 0.0174 (2.11 sigma) for the Bayesian search.
These p-values
measure the consistency of the observed track-like events with the known
atmospheric backgrounds.

The reported p-values can differ due to the estimated distance of the GW
candidate. The distance is used as a prior in Bayesian binary merger
search, while it is not
taken into account in the generic transient point-like source search.

Properties of the coincident events are shown below.

  dt        ra         dec    Angular Uncertainty(deg)  p-value(generic
transient) p-value(binary merger)
-----------------------------------------------------------------------------------------------------
 -175.94   45.21       31.74          0.43                    0.003
        0.017


where:
dt = Time offset (sec) of track event with respect to GW trigger.
Angular uncertainty = Angular uncertainty of track event: the radius of a
circle
     representing 90% CL containment by area.
Pvalue = the pvalue for this specific track event from each search.


The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector
operating at the
geographic South Pole, Antarctica. The IceCube realtime alert point of
contact can be
reached at roc@icecube.wisc.edu


[1] Baret et al., Astroparticle Physics 35, 1 (2011)
[2] PoS(ICRC2019)918 Braun et al., Astroparticle Physics 29, 299 (2008)
[3] Bartos et al. arXiv:1810.11467 (2018) and Countryman et
al.arXiv:1901.05486 (2019)

GCN Circular 27044

Subject
LIGO/Virgo S200213t: NED Galaxies in the 90% Localization Volume
Date
2020-02-13T05:17:11Z (5 years ago)
From
David Cook at IPAC/Caltech <dcook@ipac.caltech.edu>
David O. Cook (Caltech/IPAC), Angela Van Sistine (UW Milwaukee), Leo Singer (NASA/GSFC), Igor Andreoni (Caltech), Michael Coughlin (Caltech), Bob Aloisi (UW Milwaukee), Patrick R. Brady (UW Milwaukee), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), David Kaplan (UW Milwaukee), Mansi M. Kasliwal (Caltech), Joseph M. Mazzarella (Caltech/IPAC), and Marion Schmitz (Caltech/IPAC)

On behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration and the NASA/IPAC Extragalactic Database (NED) Team.

We spatially cross-matched the LIGO/Virgo S200213t trigger sky localization with the galaxies in NED and found 22,738 galaxies within the 90% containment volume. We list here the top 20 galaxies sorted by 2MASS absolute K-band magnitude.

For an extended list of galaxies in the 90% volume go to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/. This service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic followup observations.


          objname               ra      dec    DistMpc k_m_k20fe    M_Ks     dP_dV
---------------------------- -------- -------- ------- --------- ---------- --------
         ESO 101- G 004 249.5755 -64.3602  205.84     9.401 -27.166622 4.34e-09
         ESO 443- G 007 193.6709 -29.2276  238.81     9.885 -27.005278 5.61e-09
         ESO 443- G 011 193.9000 -30.3476  224.48     9.827 -26.928883 9.17e-09
              UGC 01651  32.4105  35.7975  157.10     9.157 -26.823874 1.99e-07
2MASX J00411536+4756049  10.3141  47.9347  359.86    10.963 -26.817642 1.71e-08
         MCG +03-06-037  32.3684  19.7767  273.56    10.407 -26.778292 2.84e-08
2MASX J00482152+4646379  12.0896  46.7772  377.59    11.148 -26.737125 6.43e-09
               WKK 6876 246.8634 -58.9250  199.48      9.83 -26.669447 4.94e-09
2MASX J02392281+4034032  39.8450  40.5677  330.30    10.954 -26.640547 1.14e-08
         ESO 217- G 017 179.5857 -50.9771   58.74     7.216 -26.628517 1.10e-08
2MASX J01570500+4120301  29.2708  41.3418  337.27    11.016  -26.62392 1.92e-08
             VII Zw 030  78.0703  65.1993  275.85    10.608 -26.595392 3.44e-09
         ESO 443- G 004 193.5927 -29.0130  225.27    10.172 -26.591522 6.81e-09
              UGC 01518  30.5786  19.0671  269.19    10.575 -26.575272 2.73e-08
2MASX J01552713+4130237  28.8631  41.5066  324.33    10.985 -26.569904 2.41e-08
2MASX J01340411+2752214  23.5169  27.8725  294.07    10.779  -26.56329 7.84e-09
2MASX J02015728+4615037  30.4888  46.2510  334.80    11.063  -26.56091 3.08e-08
         ESO 443- G 014 194.2425 -31.3296  235.13    10.297 -26.559544 7.82e-09
      UGC 01841 NOTES01  35.8040  42.9878  146.00     9.263 -26.558765 6.95e-08
                IC 4252 201.8667 -27.3248  189.06     9.874 -26.509014 9.26e-09


Table: Top 20 galaxies in NED that fall in the 90% probability volume for S200213t sorted by 2MASS absolute K-band magnitude. Column descriptions are as follows. name: galaxy name. ra: RA (J2000, decimal degrees). dec: Dec (J2000, decimal degrees). distmpc: galaxy distance (Mpc). k_m_k20fe: the 2MASS apparent magnitude. M_Ks: the absolute K-band magnitude derived using the 'DistMpc' column. dP_dV: the 3D probability density per cubic megaparsec at the position of each galaxy.

GCN Circular 27047

Subject
LIGO/Virgo S200213t: Neutrino and galaxies cross-match
Date
2020-02-13T06:25:53Z (5 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
V. Bhalerao (IITB), V. Karambelkar (Caltech) report on behalf of the GROWTH collaboration:

We cross-matched the IceCube neutrino candidate (IceCube collaboration, GCN 27043) with the NED galaxies list (Cook et al., GCN 27044) and the possible host galaxy list from Evans (GCN 27045). We find that the following sixteen galaxies from the NED list are within a three-sigma (1.29 degree) radius of the neutrino event. Galaxies from the Evans list are not consistent with the neutrino.

In particular, the last few galaxies are at a distance close to the median GW distance for S200213t. Further follow-up is encouraged.

objname,ra,dec,z,zunc,DistMpc,DistMod,DistMethod,Separation
UGC 02407,44.076,31.897138888889998,0.0150769996,-999.0,62.77894973754883,33.989070892333984,Kinematic,0.9763084646211937
AGC 131378,45.355,32.0175,0.019880000501871,0.00029200001154095,82.77811431884766,34.589576721191406,Kinematic,0.30359019971331863
AGC 123065,45.0025,30.98305555556,0.019917000085115,0.00011999999696855,82.93217468261719,34.5936164855957,Kinematic,0.7774047905727479
UGC 02483,45.403125,31.81925,0.0207540002,3.30000003e-05,84.30000305175781,34.6291389465332,Median,0.18229891713366353
AGC 131380,45.56666666667,30.52944444444,0.020943999290466,0.00011000000085915,87.20848846435547,34.70279312133789,Kinematic,1.2484548573639236
UGC 02393,43.97366666667,32.33491666667,0.0376829989,3.30000003e-05,134.0,35.63552474975586,Median,1.2051072750286012
UGC 02464,45.16794582152001,32.656405944970004,0.0339169987,3.30000003e-05,141.2266082763672,35.74958419799805,Kinematic,0.9170966183061067
AGC 123064,44.635,32.13388888889,0.034370001405478,0.00017299999308307,143.1128692626953,35.77839279174805,Kinematic,0.6270992408508597
AGC 123061,44.02666666667,31.28972222222,0.03583500161767,0.00033700000494719,149.2129669189453,35.86903381347656,Kinematic,1.1047174690169683
CGCG 506-002 NED02,44.91804166667,32.80027777778,0.037533,8e-05,156.2832489013672,35.96956253051758,Kinematic,1.088635020581643
V Zw 302,44.863312085939995,31.385964226389998,0.037593,0.000107,156.5330810546875,35.97303009033203,Kinematic,0.46108812734305843
AGC 123062,44.4725,31.64305555556,0.037838999181986,0.0004870000120718,157.55738830566406,35.9871940612793,Kinematic,0.6349732591350767
V Zw 294,44.54245543191,31.62150440776,0.038193,0.000133,159.03140258789062,36.007415771484375,Kinematic,0.5802981213906651
UGC 02447,44.76825,32.63052777778,0.0382560007,3.30000003e-05,174.0,36.2027473449707,Median,0.9658205967953034
UGC 02507,45.927333333330004,30.6205,0.0536740012,3.30000003e-05,223.49258422851562,36.746315002441406,Kinematic,1.276672609020272
V Zw 317,46.00830931107,31.38939240059,0.0579999983,-999.0,241.50555419921875,36.914634704589844,Kinematic,0.7652394744273816

GROWTH is a worldwide collaboration comprising of Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY,  Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; USyd, Australia; and SDSU, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.

GCN Circular 27048

Subject
LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
Date
2020-02-13T06:28:52Z (5 years ago)
From
Motoko Serino at RIKEN/MAXI <motoko@crab.riken.jp>
N. Kawai (Tokyo Tech), H. Negoro (Nihon U.),
S. Sugita, M. Serino (AGU),
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.),
M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, R. Shimomukai, M. Tominaga (JAXA),
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.),
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC)
report on behalf of the MAXI team:

We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after the LVC trigger S200213t at 2020-02-13 04:10:40.328 UTC (GCN 27042).

At the trigger time of S200213t, the high-voltage of MAXI/GSC was on.
The instantaneous field of view of GSC at the GW trigger time covered 1% of the 90% credible region
of the bayestar sky map, in which we found no significant new X-ray source.
The first one-orbit (92 min) scan observation with GSC after the event covered 99%
of the 90% credible region of the bayestar skymap from 04:10:40 to 05:42:35 UTC (T0+0 to T0+5515 sec).

No significant new source was found in the region in the one-orbit scan observation.
A typical 1-sigma averaged upper limit obtained in one scan observation
is 20 mCrab at 2-20 keV.

If you require information about X-ray flux by MAXI/GSC at specific coordinates,
please contact the submitter of this circular by email.

GCN Circular 27049

Subject
LIGO/Virgo S200213t : no neutrino counterpart candidate in ANTARES search
Date
2020-02-13T07:05:54Z (5 years ago)
From
Antoine Kouchner at ANTARES Collaboration <kouchner@apc.in2p3.fr>
M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration:

Using on-line data from the ANTARES detector, we have performed a follow-up analysis of the
recently reported LIGO/Virgo S200213t event using the 90% contour of the Initial GW_SKYMAP probability
map provided by the GW interferometers (GCN#27042). The ANTARES visibility at the time of the
alert, together with the 50% and 90% contours of the probability map are shown at http://antares.in2p3.fr/GW/S200213t_Initial.png <http://antares.in2p3.fr/GW/S200213t_Initial.png>.
Considering the location probability provided by the LIGO/Virgo collaborations, there is a
31.9% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of
the alert.

No up-going muon neutrino candidate events were recorded in the ANTARES sky during a
+/-500s time-window centered on the time 2020-02-13 04:10:40 and in the 90% contour of the S200213t
event. The expected number of atmospheric background events in the region visible by ANTARES is
1.26e-03 in the +/- 500s time window. An extended search during +/- 1 hour gives no
up-going muon neutrino coincidence. The expected number of atmospheric background events in the
region visible by ANTARES is 9.09e-03 in this larger time window.

ANTARES is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is
primarily sensitive to neutrinos in the TeV-PeV  energy range. At 10 TeV, the median angular
resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a
competitive sensitivity to this position in the sky.

GCN Circular 27050

Subject
LIGO/Virgo S200213t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
Date
2020-02-13T07:25:04Z (5 years ago)
From
James Rodi at IAPS-INAF <james.rodi@inaf.it>
James Rodi (IAPS-Roma, Italy)
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
A. Coleiro (APC, France)
S. Mereghetti (INAF IASF-Milano, Italy)

on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration

Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed a
search for a prompt gamma-ray counterpart of S200213t (GCN 27042)

At the time of the event (2020-02-13 04:10:40 UTC, hereafter T0), INTEGRAL
was operating in nominal mode. The peak of the event localization
probability was at an angle of 139 deg with respect to the spacecraft
pointing axis. This orientation implies strongly suppressed (2.8% of
optimal) response of ISGRI, somewhat suppressed (60% of optimal) response
of IBIS/Veto, and strongly suppressed (38% of optimal) response of SPI-ACS.

The background within +/-300 seconds around the event was rather stable
(excess variance 1.5).

We have performed a search for any impulsive events in INTEGRAL SPI-ACS (as
described in [2]) data.

We do not detect any significant counterparts and estimate a 3-sigma upper
limit on the 75-2000 keV fluence of 4.8e-07 erg/cm^2 (within the 50%
probability containment region of the source localization) for a burst
lasting less than 1 s with a characteristic short GRB spectrum (an
exponentially cut off power law with alpha=-0.5 and Ep=600 keV) occurring
at any time in the interval within 300 s around T0. For a typical long GRB
spectrum (Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the
derived peak flux upper limit is ~4.6e-07 (1.9e-07) erg/cm^2/s at 1 s (8 s)
time scale in 75-2000 keV energy range.

For the mean reported distance 224.0 Mpc this corresponds to the limit on
the total isotropic equivalent energy in 1 s of 2.9e+48 erg for the short
GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in
1 s (8 s) of 2.5e+48 erg/s (1.1e+48 erg/s)

We report for completeness and in order of FAP, all excesses identified in
the search region. We find: 5 likely background excesses:

T-T0 | scale | S/N | luminosity ( x 1e+48 erg/s) | FAP
-3.11 | 0.3 | 3.5 | 6.47 +/- 1.85 +/- 2.45 | 0.0691
-3.88 | 0.05 | 4 | 17.7 +/- 4.62 +/- 6.7 | 0.147
61.7 | 1.7 | 3.3 | 27.7 +/- 7.74 +/- 10.5 | 0.368
-148 | 1.1 | 3.7 | 36.7 +/- 9.64 +/- 13.9 | 0.676
254 | 0.75 | 4.1 | 4.88 +/- 1.17 +/- 1.85 | 0.974

Note that FAP estimates (especially at timescales above 2s) may be possibly
further affected by enhanced non-stationary local background noise. This
list excludes any excesses for which FAP is close to unity.



All results quoted are preliminary.

This circular is an official product of the INTEGRAL Multi-Messenger
team.

[1] Savchenko et al. 2017, A&A 603, A46
[2] Savchenko et al. 2012, A&A 541A, 122S

GCN Circular 27051

Subject
LIGO/Virgo S200213t: Candidates from the Zwicky Transient Facility
Date
2020-02-13T07:32:59Z (5 years ago)
From
Mansi M. Kasliwal at Caltech/Carnegie <mansikasliwal@gmail.com>
Mansi M. Kasliwal (Caltech), Daniel Perley (LJMU), Harsh Kumar (IITB), Igor
Andreoni (Caltech), Kishalay De (Caltech), Viraj Karambelkar (Caltech),
Varun Bhalerao (IITB), Erik Kool (OKC), Jesper Sollerman (OKC), Ana
Carracedo (OKC), Michael Coughlin (U Minn), Eric Bellm (UW), Leo Singer
(NASA GSFC), Shreya Anand (Caltech), Tomas Ahmuda (UMd)

on behalf of the ZTF and GROWTH collaborations

We observed the localization region of the gravitational wave trigger
S200213t (LVC, GCN #27042) with the Palomar 48-inch telescope equipped with
the 47 square degree Zwicky Transient Facility camera (ZTF, Bellm et al.
2019, Graham et al. 2019).

The tiling was optimally determined and triggered using the GROWTH Target
of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We
started obtaining target-of-opportunity observations in the g-band and
r-band beginning at 2020-02-13 04:36 UT, targeting ~77% of the enclosed
probability based on the bayestar skymap (LVC, GCN #27042). Each exposure
was 120s with a median depth of ~20.7 mag.

The images were processed in real-time through the ZTF reduction and image
subtraction pipelines at IPAC to search for potential counterparts (Masci
et al. 2019). Alert filtering and follow-up coordination was undertaken by
the GROWTH Marshal system (Kasliwal et al. 2019). The ZTF alert stream was
also queried using the Kowalski infrastructure (Duev et al., 2019). We
required at least 2 detections separated by at least 30 minutes to select
against moving objects. Furthermore, we cross-matched our candidates with
the Minor Planet Center to flag known asteroids. Candidates that passed our
selection are:

+--------------+----------+-------------+--------------+--------+------+----------+-------+
|     Name     | IAU Name |      RA     |     Dec      | filter | mag  |
MJD    | Notes |
+--------------+----------+-------------+--------------+--------+------+----------+-------+
| ZTF20aamvqxl |    AT2020ciy    | 01:56:57.10 | +53:40:07.97 |   r    |
20.1 | 58892.22 | Offset from Host Galaxy |
| ZTF20aamvnth |    AT2020cjb    | 01:13:21.05 | +49:38:43.94 |   g    |
20.4 | 58892.20 | Offset from Host Galaxy      |
| ZTF20aamvoxx |    AT2020cjg    | 02:37:35.78 | +26:55:14.22 |   g    |
20.0 | 58892.21 | SDSS phot-z 0.110 +/- 0.008      |
| ZTF20aamvtip |    AT2020cje    | 02:32:19.81 | +27:48:36.34 |   r    |
20.6 | 58892.24 | SDSS phot-z 0.22 +/- 0.06 |
| ZTF20aamvnat |    AT2020ciz    | 01:48:57.49 | +56:21:16.49 |   g    |
19.0 | 58892.21 | Faint Red Counterpart in PS1      |
| ZTF20aamvmzj |    AT2020cja    | 01:48:45.41 | +51:25:49.73 |   g    |
20.6 | 58892.20 | Hostless       |
| ZTF20aamvoeh |    AT2020cjc    | 02:14:00.48 | +38:56:10.74 |   g    |
20.6 | 58892.21 | Nuclear/Stellar?       |
| ZTF20aamvodd |    AT2020cjf    | 02:29:55.77 | +50:19:09.94 |   g    |
19.7 | 58892.20 | Faint Red Counterpart in PS1      |
+--------------+----------+-------------+--------------+--------+------+----------+-------+

We encourage follow-up to classify the candidates. We caution that these
candidates are low Galactic latitude and the magnitudes reported are not
extinction corrected.

ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC,
USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY,
Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan;
IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia.
ZTF acknowledges the generous support of the NSF under AST MSIP Grant No
1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant
No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et
al. 2019). Alert filtering and follow-up coordination is being undertaken
by the GROWTH marshal system (Kasliwal et al. 2019). Alert database
searches are done with using the Kowalski infrastructure (Duev et al.,
2019) and with AMPEL (Nordin et al. 2019).

GCN Circular 27055

Subject
LIGO/Virgo S200213t: upper limits from AGILE/GRID observations
Date
2020-02-13T09:27:53Z (5 years ago)
From
Francesco Longo at U of Trieste,INFN Trieste <franzlongo1969@gmail.com>
F. Longo (Univ. Trieste, and INFN Trieste), G. Piano, C. Casentini
(INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
M. Cardillo, A. Ursi (INAF/IAPS), F. Lucarelli, C. Pittori, F. Verrecchia
(SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, N. Parmiggiani
(INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), report on behalf of
the AGILE Team:

In response to the LIGO-Virgo GW event S200213t at T0 = 2020-02-13
04:10:40.328 (UTC) a preliminary analysis of the AGILE exposure at T0
shows that the Gamma-Ray Imaging Detector (GRID) exposure covered
the 32% of the 90% c.l. localization region (LR) (4% of 90% c.l. LR is
occulted by Earth).

We performed an analysis of the GRID data in the energy range
50 MeV - 10 GeV on T0, where good exposure of the S200213t 90%
c.l. LR was available.

No candidate gamma-ray transient was detected.

The following preliminary GRID values of 3-sigma upper limit (UL) are
obtained:

from 8.7e-07 to 7.2e-06 erg cm^-2 s^-1, with exposure of about 32% of
the LR over the time interval ( T0 -2s ; T0 + 2s );
from 3.3e-07 to 6.4e-06 erg cm^-2 s^-1, with exposure of about 38% of
the LR over the time interval ( T0s ; T0 + 10s );
from 3e-08 to 1.5e-06 erg cm^-2 s^-1, with exposure of about 48% of
the LR over the time interval ( T0s ; T0 + 100s );

These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.

GCN Circular 27056

Subject
LIGO/Virgo S200213t: not observable by Fermi-GBM
Date
2020-02-13T12:49:57Z (5 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
P. Veres (UAH) reports on behalf of the Fermi-GBM Team and the
GBM-LIGO/Virgo group:

At the time of S200213t (2020-02-13 04:10:40 UT), Fermi was passing through
the South Atlantic Anomaly from 9.9 minutes prior to 14.1 minutes after the
trigger time; therefore the GBM detectors were disabled.

GCN Circular 27058

Subject
LIGO/Virgo S200213t: Swift/BAT in the South Atlantic Anomaly
Date
2020-02-13T17:22:16Z (5 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (NASA/GSFC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB),
A. A. Breeveld (MSSL-UCL), D. N. Burrows (PSU),
S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASI-ASDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU),
N. Klingler (PSU), H. A. Krimm (NSF),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), J. A. Nousek (PSU),
S. R. Oates (U. of Birmingham), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U. Toronto),
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:

Around the trigger time (T0) of LIGO/Virgo S200213t
(LIGO/VIRGO Collaboration GCN Circ. 27042),
Swift/BAT was in the South Atlantic Anomaly (SAA)
from T0-46 s to T0+863 s. Therefore, no science data
were collected during this time.

The results of the BAT analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S200213t/web/source_public.html

GCN Circular 27059

Subject
LIGO/Virgo S200213t: MANGROVE catalog galaxy ranking
Date
2020-02-13T17:45:04Z (5 years ago)
From
Jean-Gregoire Ducoin at LAL <ducoin@lal.in2p3.fr>
J.-G. Ducoin (IJCLab), D. Corre (IJCLab), N. Leroy (IJCLab), E. Le Floch (IRFU/CEA)

On behalf of the Mass AssociatioN for GRavitational waves ObserVations
Efficiency (MANGROVE) Team.

We spatially cross-matched the LIGO/Virgo S200213t event skymap
(90% probability volume) with the MANGROVE [1] galaxy catalog
and found 33991 compatible galaxies. We classified as "compatible"       
with the skymap, a galaxy which fulfills the two following conditions:

-Its 2D position in the sky has to be in the 90% of the 2D skymap
probability distribution.
-Its distance has to fall within the 3 sigma distance error
localization at the position of the galaxy.

We rank galaxies according to the grade Gtot presented in
Ducoin et al. [1] which uses the galaxies stellar mass in addition to
their localisation to assess their probability of hosting the event.
The stellar mass is estimated from the WISE1 luminosity. 
The list of the 20 first galaxies ranked by this grade is given below,
the full list of galaxies is available at https://mangrove.lal.in2p3.fr

+--------+------------------------+---------+---------+-----------+------------+---------+
|   Rank | Name                   |      RA |     DEC |    log(M) |   AGN_flag |    Gtot |
|        |                        |   [deg] |   [deg] |   [M_sun] |            |         |
+========+========================+=========+=========+===========+============+=========+
|      1 | 2MASS 01192705+5831151 |  19.863 |  58.521 |      11.3 |          0 | 3.7e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      2 | HyperLEDA 137452       |  15.442 |  55.949 |      11.2 |          0 | 3.4e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      3 | HyperLEDA 137873       |  22.541 |  57.846 |      11.2 |          0 | 2.7e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      4 | HyperLEDA 2413196      |  14.865 |  52.367 |      10.9 |          0 | 2.4e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      5 | GWGC PGC137746         |  20.290 |  57.658 |      11.0 |          0 | 2.3e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      6 | 2MASS 01103706+5536121 |  17.654 |  55.603 |      10.8 |          0 | 2.2e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      7 | HyperLEDA 2410161      |  15.600 |  52.243 |      10.8 |          0 | 2.0e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      8 | 2MASS 01182764+5821363 |  19.615 |  58.360 |      11.0 |          0 | 2.0e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|      9 | 2MASS 01192582+5824261 |  19.858 |  58.407 |      11.0 |          0 | 1.8e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     10 | GWGC PGC089894         |  21.124 |  56.182 |      11.1 |          0 | 1.8e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     11 | 2MASS 01131453+5410558 |  18.311 |  54.182 |      10.7 |          0 | 1.8e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     12 | GWGC NGC0020           |   2.386 |  33.309 |      11.1 |          0 | 1.6e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     13 | 2MASS 01020132+5558266 |  15.506 |  55.974 |      10.7 |          0 | 1.6e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     14 | HyperLEDA 2318158      |   9.727 |  48.468 |      11.3 |          0 | 1.5e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     15 | 2MASS 01044353+5137119 |  16.181 |  51.620 |      10.7 |          0 | 1.5e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     16 | 2MASS 01085147+5453309 |  17.214 |  54.892 |      10.6 |          0 | 1.5e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     17 | HyperLEDA 2389143      |  13.787 |  51.145 |      10.7 |          0 | 1.4e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     18 | HyperLEDA 3574         |  14.987 |  47.786 |      11.4 |          0 | 1.4e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     19 | 2MASS 00580831+5358326 |  14.535 |  53.976 |      10.6 |          0 | 1.4e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+
|     20 | 2MASS 01155827+5806430 |  18.993 |  58.112 |      10.7 |          0 | 1.4e-03 |
+--------+------------------------+---------+---------+-----------+------------+---------+

Where the grade Gtot is defined in [1], M is the stellar mass,
AGN_flag is equal to 1 if the source is identified
as AGN from mid-infrared color criterion [1], 0 otherwise.

The estimated mass completeness of the catalog for the skymap
distance is about 56%.
This calculation was made by comparing the total mass within
the Mangrove catalog to the stellar mass function derived from
the GAMA survey [4] in the range 224 +/- 90Mpc (within 1 sigma
of the skymap [1]).

The MANGROVE catalog compiles information from the GLADE
catalog [2] and AllWISE catalog [3] up to 400Mpc and is
fully available on the MANGROVE website
(https://mangrove.lal.in2p3.fr). This website
also provides tools to download a complete list of
compatible galaxies for every gravitational wave event
below 400Mpc of the LVC O3 run with the possibility to add
observational constraints.

[1] Ducoin et al., ui.adsabs.harvard.edu/abs/2020MNRAS.492.4768D/abstract
[2] D��lya et al., ui.adsabs.harvard.edu/abs/2018MNRAS.479.2374D
[3] Cutri et al., ui.adsabs.harvard.edu/abs/2014yCat.2328....0C
[4] Wright et al., 2017, MNRAS, 470, 283

GCN Circular 27060

Subject
LIGO/Virgo S200213t: AT2020ciy/ZTF20aamvqxl, AT2020cjg/ZTF20aamvoxx and AT2020cje/ZTF20aamvtip 10.4m GTC spectroscopy
Date
2020-02-13T23:06:46Z (5 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
A. F. Valeev (SAO-RAS), Y.-D. Hu, A. J. Castro-Tirado and E. 
Fernandez-Garcia (IAA-CSIC), V. Sokolov (SAO-RAS), I. Carrasco and A. 
Castellon (UMA) and G. Lombardi (GRANTECAN, IAC, ULL), on behalf of a 
larger collaboration, report:

Following the detection of AT2020ciy/ZTF20aamvqxl, 
AT2020cjg/ZTF20aamvoxx and AT2020cje/ZTF20aamvtip (Kasliwal et al. GCNC 
27051) within the error area of the GW event S200213t (LVC, GCNC 27042), 
we obtained optical spectra covering the range 3700-7400 A with the 
10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) starting on 
Feb 13, 20:08 UT. Details follow:

AT2020ciy/ZTF20aamvqxl, a magnitude r'=20.04 +/- 0.03 on 21:29UT is 
derived. The GTC spectrum is consistent with a SNIa at redshift z = 
0.1018 +/- 0.0005.

AT2020cjg/ZTF20aamvoxx, a magnitude r'=18.19 +/- 0.07 on 20:33UT is 
derived. The GTC spectrum is consistent with a SNIa at redshift z = 
0.097 +/- 0.005.

AT2020cje/ZTF20aamvtip, a magnitude r'=20.08 +/- 0.02 on 20:55UT is 
derived. The GTC spectrum is consistent with a SNIa at redshift z = 
0.1512 +/- 0.0005.

Therefore we consider that AT2020ciy/ZTF20aamvqxl, 
AT2020cjg/ZTF20aamvoxx and AT2020cje/ZTF20aamvtip are unrelated to the 
S200213t GW alert.

GCN Circular 27061

Subject
LIGO/Virgo S200213t: No Counterparts in DDOTI/OAN Optical Observations
Date
2020-02-13T23:46:25Z (5 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), Margarita Pereyra (UNAM),
William H. Lee (UNAM), Simone Dichiara (GSFC/UMD), Alexander Kutyrev
(GSFC/UMD), Margarita Pereyra (UNAM), Rosa L. Becerra (UNAM), Diego
Gonzalez (UNAM), Eleonora Troja (GSFC/UMD), and Tanner Wolfram (ASU)
report:

We observed LIGO/Virgo S200213t (Singer et al, GCN Circ. 27042) with the
DDOTI/OAN wide-field imager at the Observatorio Astronomico Nacional on
Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of
2020-02-13 UTC.

We tiled the LVC localization with three pointings centered on
00:50:27.6 +49:57:20, 01:09:34.1 +55:40:56, and 01:46:40.1 +57:01:56
(J2000). The combined field covers about 200 square degrees and includes
about 50% of the probability in the current BAYESTAR map.

We observed from 2020-02-13 04:55 UTC to 2020-02-13 07:05 UTC (from 0.75
to 2.92 hours after the event) obtaining exposures of 24 to 44 minutes
across the field in the w filter. We calibrate our images against the
APASS catalog. Our 10-sigma limiting magnitude are between w = 18.7 and
w = 19.2.

Comparing our observations to the USNO-B1 and PanSTARRS PS1 DR2
catalogs, with the exception of Comet C/2017 T2, we detect no
uncatalogued sources within the observed field to our 10-sigma limit.

We thank the staff of the Observatorio Astronomico Nacional in San Pedro
Martir.

GCN Circular 27062

Subject
LIGO/Virgo S200213t: No counterpart candidates in Fermi-LAT observations
Date
2020-02-14T00:32:01Z (5 years ago)
From
Milena Crnogorcevic at U.of Maryland/NASA-GSFC <milenaGCN@gmail.com>
S. Cutini (INFN Perugia), M. Crnogorcevic (Univ. of Maryland &
NASA/GSFC), M. Axelsson (KTH & Stockholm Univ), E. Bissaldi
(Politecnico & INFN Bari),
D. Kocevski (NASA/MSFC), N. Omodei (Stanford Univ.), and F. Longo
(University and INFN, Trieste)
report on behalf of the Fermi-LAT Collaboration:

We have searched data collected by the Fermi Large Area Telescope (LAT) on
February 13, 2020, for possible high-energy (E > 100 MeV) gamma-ray emission in
spatial/temporal coincidence with the LIGO/Virgo trigger S200213t (GCN  27042).

We define "instantaneous coverage" as the integral over the region of the LIGO
probability map that is within the LAT field of view at a given time,
and "cumulative
coverage" as the integral of the instantaneous coverage over time.

The Fermi Gamma-ray Space Telescope was passing through the South Atlantic
Anomaly (SAA) at the time of the trigger (T0 = 2020-02-13 04:10:40.330 UTC).
During SAA passages both the LAT and the Gamma-ray Burst Monitor (GBM) do not
collect data due to the high charged particle background in this region. The LAT
resumed taking data upon exiting the SAA at roughly T0 + 1000 s. At
that time the
instantaneous coverage was 33% of the LIGO probability map, and reached
100% cumulative coverage after T0 + 3 ks.

We performed a search for a transient counterpart within the observed region of
the 90% contour of the LIGO map in a fixed time window from T0 + 1 ks
to T0 + 10 ks.
No significant new sources are found.

We also performed a search which adapted the time interval of the
analysis to the
the exposure of each region of the sky, and no additional excesses were found.

Energy flux upper bounds for the fixed time interval between 100 MeV and 1 GeV
for this search vary between 8.6e-11 and 1.9e-9 [erg/cm^2/s].

The Fermi-LAT point of contact for this event is
Sara Cutini (sara.cutini@pg.infn.it)

The Fermi-LAT is a pair conversion telescope designed to cover
the energy band from 20 MeV to greater than 300 GeV
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.

GCN Circular 27063

Subject
LIGO/Virgo S200213t: AT2020ciz/ZTF20aamvnat, AT2020cjb/ZTF20aamvnth and 2020cjf/ZTF20aamvodd 10.4m GTC spectroscopy
Date
2020-02-14T05:52:57Z (5 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
A. J. Castro-Tirado, Y.-D. Hu (IAA-CSIC), A. F. Valeev and V. Sokolov 
(SAO-RAS), E. Fernandez-Garcia (IAA-CSIC), I. Carrasco and A. Castellon 
(UMA), M. D. Caballero-Garcia (ASU-CAS), S. B. Pandey (ARIES) and G. 
Lombardi (GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report:

Following the detection of AT2020ciz/ZTF20aamvnat, 2020cjf/ZTF20aamvodd 
and AT2020cjb/ZTF20aamvnth (Kasliwal et al. GCNC 27051) within the error 
area of the GW event S200213t (LVC, GCNC 27042), we obtained optical 
spectra covering the range 3700-7400 A with the 10.4m GTC telescope 
equipped with OSIRIS in La Palma (Spain) starting on Feb 13, 20:08 UT. 
Details follow:

For AT2020ciz/ZTF20aamvnat, a magnitude r'= 19.08 +/- 0.03 at 21:11 UT 
is derived. The GTC spectrum shows double-peaked emission 
lines**(H-alpha, H-beta, H-gamma, He I 5876, He II 4686) at z = 0, all 
consistent with a cataclysmic variable in our Galaxy.

For AT2020cjb/ZTF20aamvnth, a magnitude r'= 20.33 +/- 0.03 at 20:13 UT 
is derived. The GTC spectrum is consistent with a SN IIp (about 6 days 
after the maximum) at z = 0.0612 +/- 0.0005.

For 2020cjf/ZTF20aamvodd, a magnitude r'= 24.5 + /- 0.3 at 22:42 UT is 
derived, implying a decay in brightness of about 4.5 mag when comparing 
to the reported ZTF value 18 h earlier (GCNC 27051). The low S/N ratio 
GTC spectrum shows a H-alpha emission line at z=0 superimposed on a red 
continuum starting from ~6000 A. We conclude that this object is a red 
dwarf in our Galaxy.

Therefore we consider that AT2020ciz/ZTF20aamvnat, 
AT2020cjb/ZTF20aamvnth and 2020cjf/ZTF20aamvodd are unrelated to the 
S200213t GW alert.

GCN Circular 27064

Subject
LIGO/Virgo S200213t: No counterpart candidates in KAIT observations
Date
2020-02-14T06:49:44Z (5 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Sergiy Vasylyev, James Sunseri, Nachiket Girish, Yukei Murakami,
WeiKang Zheng, and Alexei V. Filippenko (UC Berkeley) report
on behalf of the Lick/KAIT GW follow-up team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, observed the 90% region of the gravitational-wave
event S200223t (GCN 27042) detected by LIGO/Virgo. More than
one thousand galaxies were selected from the Glade catalog V1.0
(Dalya et al., 2018, MNRAS, 479, 2374; http://aquarius.elte.hu/glade/)
according to their priority score. KAIT observed 108 of them based on
their priority scores and elevation visibility, with each clear-filter
exposure time being 60 s. The first image was taken at 04:20:06, Feb.
13th UT, about 10 minutes after the trigger, and the last image at
12:02:48 UT. Our typical limiting mag is 18.0. No viable counterparts
were identified and the analysis is ongoing. A full list of galaxies
observed by KAIT is given below.

GladeID   UT(Feb13)  RA_J2000   Dec_J2000
-----------------------------------------------
G0703055  04:20:06  01:37:16.9555  +28:53:25.6236
G0736143  04:21:24  01:38:15.4706  +41:39:14.7564
G0245728  04:22:33  01:38:22.5434  +44:54:18.1476
G0010464  04:23:49  01:38:31.3097  +28:43:24.5892
G1311531  04:25:06  01:40:43.6656  +42:52:49.9116
G0825474  04:26:24  01:43:08.0278  +27:45:02.2788
G0761627  04:27:33  01:44:08.941   +31:19:15.4308
G1179856  04:28:55  01:44:12.2213  +50:26:51.6804
G0748031  04:30:12  01:44:38.3436  +38:12:09.7956
G0035087  04:31:22  01:44:42.7589  +42:44:15.4932
G0690328  04:32:35  01:45:10.1866  +32:07:23.5596
G0405612  04:33:58  01:45:38.016   +55:17:11.8788
G0410414  04:35:15  01:46:36.1848  +62:47:16.2996
G0652952  04:36:43  01:46:56.4482  +32:06:35.4672
G0549449  04:37:52  01:46:57.882   +28:45:22.122
G0789116  04:39:12  01:48:22.4606  +11:31:17.6376
G1333135  04:40:48  01:48:28.603   +64:09:00.144
G0593564  04:42:24  01:49:14.0635  +13:03:18.882
G0004616  04:43:40  01:50:14.0066  +27:38:44.412
G0672407  04:44:53  01:50:33.149   +33:37:35.1624
G0718267  04:46:02  01:50:46.841   +32:32:48.174
G0757472  04:47:12  01:51:23.551   +33:01:52.32
G1073061  04:48:38  01:51:25.2182  +59:41:03.0372
G0567029  04:50:08  01:51:36.2434  +19:06:12.726
G1336557  04:51:36  01:29:19.2192  +44:06:53.5788
G1135494  04:59:17  02:25:42.9089  +25:47:05.0028
G0610878  05:00:35  02:25:45.1922  +37:13:54.0804
G0802092  05:01:50  02:25:47.635   +27:14:33.0144
G0570221  05:03:00  02:26:11.1785  +26:03:19.314
G0554443  05:04:09  02:26:12.4603  +27:36:12.312
G0031826  05:05:18  02:26:15.185   +26:06:23.3208
G0705834  05:06:28  02:26:20.7175  +30:26:44.3832
G0569632  05:07:37  02:26:26.0815  +27:39:15.2964
G0577157  05:08:46  02:26:33.0432  +29:49:50.2572
G0482933  05:09:58  02:27:45.8359  +28:12:33.2496
G0625241  05:11:07  02:27:46.4117  +26:35:22.2576
G0710754  05:12:16  02:28:03.6108  +28:10:31.2528
G0693481  05:13:29  02:29:13.9901  +23:04:57.99
G0722977  05:14:41  02:29:38.8954  +28:59:15.4104
G0399203  05:15:58  02:31:40.0517  +39:22:42.1536
G0659049  05:17:16  02:33:14.3225  +25:30:22.122
G0012872  05:18:31  02:33:42.4769  +37:40:03.1512
G0758273  08:50:24  12:33:04.1858  -32:53:13.2036
G0575179  08:51:37  12:42:57.5573  -31:54:41.9796
G0622596  08:52:49  12:58:13.7806  -26:20:23.0532
G0557442  08:54:00  13:00:40.0817  -33:58:23.952
G0571203  08:55:15  13:06:08.5656  -31:29:08.124
G0770342  08:56:27  13:07:11.4185  -31:41:56.2812
G0571043  08:57:38  13:17:45.271   -24:19:10.632
G0735821  08:58:47  13:18:55.0817  -24:41:48.534
G0562664  08:59:59  13:21:15.1649  -27:14:59.3556
G0592695  09:01:10  13:22:06.7457  -31:46:16.1076
G0752765  09:02:22  13:22:56.825   -32:43:42.3948
G0717660  09:03:33  13:23:28.0334  -24:03:29.1996
G0507238  09:04:43  13:26:35.2442  -26:44:30.8436
G0704596  09:05:57  13:27:29.6119  -31:23:23.7012
G0971608  09:07:08  13:30:49.0723  -25:20:00.9852
G0731423  09:08:18  13:33:08.3971  -23:32:38.6916
G0004813  09:09:30  13:36:34.7167  -26:33:13.9032
G0558588  09:11:53  13:40:19.9037  -23:51:29.1852
G0571193  09:13:06  13:47:40.0891  -30:56:22.524
G0754515  10:40:31  13:22:53.91    -32:40:13.4364
G0582873  10:41:40  13:22:55.7042  -31:44:16.3968
G0612607  10:42:50  13:23:44.5056  -27:59:31.9488
G0744268  10:43:59  13:24:57.6893  -27:32:34.6524
G0800065  10:45:06  13:25:08.0897  -27:49:09.624
G0670296  10:46:16  13:26:10.5799  -27:25:38.6004
G0667166  10:48:40  13:26:47.915   -25:05:46.8096
G0684835  10:49:49  13:27:04.8634  -26:59:35.9268
G0589723  10:51:00  13:28:09.4922  -34:02:24.8136
G0563957  10:52:11  13:28:14.9304  -27:58:36.4908
G0650981  10:53:21  13:28:41.2536  -25:35:51.1512
G0696294  10:54:30  13:29:01.7028  -28:50:22.8192
G0571527  10:56:53  13:29:28.158   -30:08:05.802
G0390714  10:58:02  13:29:47.677   -28:00:22.824
G0640528  10:59:11  13:30:23.0933  -28:16:14.1024
G0574002  11:00:22  13:30:58.4546  -21:50:51.1764
G0736960  11:01:34  13:31:39.8292  -33:14:34.1268
G0631679  11:02:45  13:32:34.0027  -27:26:55.8348
G0983556  11:05:08  13:40:49.464   -32:39:27.7884
G0662200  11:06:17  13:48:06.3758  -33:27:48.492
G0609725  11:07:26  13:53:40.763   -33:56:57.5304
G0585582  11:08:37  13:56:13.0956  -27:44:58.2756
G0604074  11:09:58  15:13:26.3086  -07:21:39.9348
G0551346  11:11:09  15:15:10.1806  -14:37:00.7392
G1024857  11:12:18  15:25:11.9861  -17:14:38.328
G0584498  11:14:45  15:30:43.601   -22:46:06.6468
G0598294  11:38:54  15:33:20.7166  -08:42:01.962
G0609950  11:40:13  15:33:45.8239  -32:00:17.0028
G0659116  11:41:22  15:34:01.4539  -28:37:46.4124
G0628445  11:42:34  15:34:57.8431  -31:55:40.4976
G0577569  11:43:48  15:35:04.7606  -17:54:44.4672
G0706124  11:44:57  15:36:38.053   -18:47:10.8744
G0608661  11:46:08  15:39:28.7256  -25:48:15.7356
G0592968  11:47:18  15:39:47.7979  -25:48:50.508
G0766921  11:48:28  15:41:39.5215  -25:39:13.1616
G1202253  11:49:37  15:41:59.4142  -26:29:38.7672
G0337511  11:50:47  15:42:16.3294  -29:23:57.7176
G0943816  11:52:00  15:44:21.881   -33:23:04.2648
G0669691  11:53:12  15:44:30.8496  -24:47:15.3456
G0905299  11:54:25  15:45:51.4819  -33:27:29.8044
G0714080  11:55:39  15:52:26.693   -21:44:36.8664
G0652719  11:56:52  15:54:51.6797  -31:22:41.7144
G0122553  11:58:04  15:56:49.6764  -32:59:58.5456
G0656282  11:59:15  15:57:42.0593  -30:23:34.6956
G0691782  12:00:25  16:05:37.6025  -28:51:34.7652
G0722439  12:01:36  16:07:38.4814  -33:04:12.5904
G0630803  12:02:48  16:07:50.5517  -31:53:47.9616

GCN Circular 27065

Subject
LIGO/Virgo S200213t: More Candidates from the Zwicky Transient Facility
Date
2020-02-14T07:20:05Z (5 years ago)
From
Igor Andreoni at Caltech <igor.andreoni@gmail.com>
Igor Andreoni (Caltech), Harsh Kumar (IITB), Viraj Karambelkar (Caltech), Mansi M. Kasliwal (Caltech), Varun Bhalerao (IITB), Shreya Anand (Caltech), Michael Coughlin (U Minn), Robert Stein (DESY), Eric Bellm (UW), Leo Singer (NASA GSFC), Tomas Ahmuda (UMd)

on behalf of the ZTF and GROWTH collaborations

We continued to observe the localization region of the gravitational wave trigger S200213t (BAYESTAR skymap; LVC, GCN #27042) with the Palomar 48-inch telescope equipped with the 47 square degree Zwicky Transient Facility camera (ZTF, Bellm et al. 2019, Graham et al. 2019). A first list of 8 candidates was presented in Kasliwal et al. (GCN #27051), 6 of which were spectroscopically classified with 10.4m GTC as transients unrelated with S200213t (Valeev et al., GCN #27060; Castro-Tirado et al., GCN #27063).

The ZTF tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). Alert filtering and follow-up coordination was undertaken by the GROWTH Marshal system (Kasliwal et al. 2019). The ZTF alert stream was also queried using Kowalski (Duev et al., 2019) and AMPEL (Nordin et al. 2019). We required at least 2 detections separated by at least 15 minutes to select against moving objects. Furthermore, we cross-matched our candidates with the Minor Planet Center to flag known asteroids. 

In addition to those sources already reported by Kasliwal et al. (GCN #27051), candidates that passed our selection and that are enclosed in the 90% probability region of the BAYESTAR skymap are:

+--------------+-----------+-------------+--------------+--------+------+----------+-------+
|     Name     |  IAU Name |      RA     |     Dec      | filter | mag  |   MJD    | Notes |
+--------------+-----------+-------------+--------------+--------+------+----------+-------+
| ZTF20aanakwb | AT2020cls | 00:26:05.17 | +42:46:25.40 |   g    | 21.0 | 58893.11 |  (a)  |
| ZTF20aanaltd | AT2020clt | 00:38:57.76 | +43:26:27.85 |   g    | 20.8 | 58893.11 |  (b)  |
| ZTF20aanaksk | AT2020clu | 01:17:44.55 | +31:10:28.18 |   g    | 20.5 | 58893.11 |  (c)  |
| ZTF20aanallx | AT2020clv | 00:25:28.00 | +51:13:24.20 |   g    | 21.1 | 58893.10 |  (b)  |
| ZTF20aanaoyz | AT2020clw | 01:38:22.58 | +23:22:56.12 |   g    | 21.5 | 58893.11 |  (d)  |
| ZTF20aamvpvx | AT2020clx | 02:07:45.67 | +20:01:50.21 |   g    | 20.3 | 58892.21 |  (e)  |
+--------------+-----------+-------------+--------------+--------+------+----------+-------+
(a) Faint source underneath (star/galaxy?)
(b) Offset from the possible host 
(c) Blue; hostless
(d) On top of a faint source with SDSS photoz = 0.504 (Alam et al., 2015)
(e) Nuclear; SDSS photoz = 0.0755 +- 0.0176 (Alam et al., 2015); GLADE v2.3 catalog z = 0.0613 (Dalya et al., 2018) 

We encourage follow-up to classify the new candidates.


ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert filtering and follow-up coordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). Alert database searches are done with using the Kowalski infrastructure (Duev et al., 2019) and with AMPEL (Nordin et al. 2019).

GCN Circular 27066

Subject
LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
Date
2020-02-14T09:50:57Z (5 years ago)
From
Hiroki Onozato at University of Hyogo <onozato@nhao.jp>
A. Kaneko (Konan U.); M. Sasada, K. Takagi, T. Nakaoka (Hiroshima U.); K. Yanagisawa (NAOJ); H. Onozato, J. Takahashi (U. Hyogo); R. Adachi, K. L. Murata (Tokyo Tech); Y. Utsumi (Stanford/SLAC) on behalf of J-GEM collaboration

We report imaging observations for the gravitational wave event S200213t (LVC, GCNC 27042). We started our observations from 2020-02-13 09:39 UT (MJD=58892.40) about 5 hours after the event and ended at 2020-02-13 15:57 UT (MJD=58892.66).

We performed galaxy-targeted observations for 23 galaxies (see the Table 1 below) selected from the GLADE catalog (Dalya et al. 2018) in the probability skymap of S200213t using the following telescopes and instruments. In addition, we also observed 7 candidates from the Zwicky Transient Facility (Kasliwal et al. GCNC 27051; Table 2) and, 14 galaxies selected from a combination of the IceCube localization (Hussain
, GCNC 27043; Table 3) and the GW probability map. In this GW+IceCube region a cumulative probability to have a GW source reaches 95% by assuming that the source resides in GLADE galaxies.

We found no apparent transients except for variable stars around these galaxies to 5 sigma limiting magnitudes in the AB system listed below.

1) GW+GLADE
     galid          ra       dec      dist    J    Ks   H    R            obsid         
--------------- --------- --------- -------- ---- ---- ---- ---- -----------------------
GL005854+523636 14.7256   52.6099   138.8231 --   --   18.7 --   Kanata-HONIR           
GL010146+555656 15.4418   55.9488   179.8459 17.6 --   18.7 --   OAOWFC,Kanata-HONIR    
GL011543+555948 18.9286   55.9965   174.9892 19.4 --   --   --   Nayuta-NIC             
GL010310+553446 15.793    55.5794   177.5464 --   --   16.5 --   Kanata-HONIR           
GL010503+555058 16.2611   55.8494   178.6891 18.9 19.5 --   --   Nayuta-NIC             
GL004920+531429 12.334    53.2413   147.7597 --   16.4 --   --   Nayuta-NIC             
GL012430+561056 21.1237   56.1821   83.7757  19.1 19.0 19.2 --   Nayuta-NIC             
GL010851+545331 17.2145   54.8919   196.9834 --   20.3 20.4 --   Nayuta-NIC             
GL005717+514522 14.3211   51.7562   121.0417 --   --   18.8 19.8 Kanata-HONIR           
GL000719+323633 1.8312    32.609    78.7447  --   --   18.0 18.9 Kanata-HONIR           
GL012156+560137 20.4824   56.027    182.1745 17.2 16.2 --   --   Nayuta-NIC             
GL011037+553612 17.6544   55.6034   195.0742 --   --   19.3 20.1 Nayuta-NIC,Kanata-HONIR
GL011830+515644 19.6266   51.9456   130.2309 --   17.8 19.0 --   Nayuta-NIC             
GL010327+522854 15.862    52.4816   206.8819 18.1 --   --   --   OAOWFC                 
GL010201+555827 15.5055   55.9741   176.4314 17.6 --   18.7 --   OAOWFC,Kanata-HONIR    
GL005900+523856 14.7461   52.6488   133.1371 --   --   18.7 19.4 Kanata-HONIR           
GL010337+555008 15.9045   55.8357   128.2277 17.6 --   --   --   OAOWFC                 
GL005854+523635 14.7255   52.6097   141.3821 --   --   18.7 19.4 Kanata-HONIR           
GL010335+522542 15.8939   52.4282   147.7146 18.1 --   --   --   OAOWFC                 
GL000720+323633 1.8313    32.6093   79.2514  --   --   18.0 18.9 Kanata-HONIR           
GL011834+564202 19.642    56.7007   244.2131 --   --   17.3 17.8 Kanata-HONIR           
GL011004+553941 17.5162   55.6615   252.3077 --   --   19.3 20.1 Kanata-HONIR           
GL004534+551329 11.3898   55.2248   179.5863 --   --   18.3 19.1 Kanata-HONIR          

2) ZTF candidates
     galid          ra       dec     J    Ks   H    R            obsid         
--------------- --------- --------- ---- ---- ---- ---- -----------------------
ZTF20aamvmzj    27.189208 51.430481 --   18.0 18.7 Kanata-HONIR           
ZTF20aamvnat    27.239542 56.354581 --   16.7 17.6 Kanata-HONIR           
ZTF20aamvodd    37.482375 50.319428 19.2 19.7 --   Nayuta-NIC             
ZTF20aamvoeh    33.502    38.936317 18.5 18.9 --   Nayuta-NIC             
ZTF20aamvoxx    39.399083 26.920617 17.0 17.4 --   Nayuta-NIC             
ZTF20aamvqxl    29.237917 53.668881 --   18.3 18.8 Kanata-HONIR           
ZTF20aamvtip    38.082542 27.810094 --   17.9 18.9 Nayuta-NIC,Kanata-HONIR

3) GW+IceCube+GLADE
    galid         ra     dec     dist    G    R    I    J          obsid        
--------------- ------- ------- -------- ---- ---- ---- ---- --------------------
GL030126+313509 45.3577 31.5859 254.0222 18.8 18.9 18.2 --   MITSuME-Akeno       
GL025927+312309 44.8633 31.3859 169.073  19.0 19.2 18.7 18.8 MITSuME-Akeno,OAOWFC
GL030137+314909 45.4031 31.8192 91.7745  18.8 18.9 18.2 --   MITSuME-Akeno       
GL025810+313717 44.5423 31.6215 172.3614 19.1 19.3 18.8 --   MITSuME-Akeno       
GL030141+315341 45.4207 31.8948 97.1384  18.8 18.9 18.2 --   MITSuME-Akeno       
GL030043+311155 45.1789 31.1987 248.807  --   --   --   18.8 OAOWFC              
GL025754+313801 44.4768 31.6337 232.8442 19.1 19.3 18.8 --   MITSuME-Akeno       
GL030039+311813 45.163  31.3037 324.3176 --   --   18.7 18.8 MITSuME-Akeno,OAOWFC
GL030403+314213 46.0139 31.7036 257.8736 19.1 19.1 18.3 --   MITSuME-Akeno       
GL030342+314522 45.927  31.756  382.0309 19.1 19.1 18.3 --   MITSuME-Akeno       
GL030402+312322 46.0084 31.3895 226.1783 19.1 19.1 18.3 --   MITSuME-Akeno       
GL030206+321824 45.5263 32.3068 167.3166 18.8 19.2 18.6 --   MITSuME-Akeno       
GL030204+322400 45.5168 32.4001 250.7152 18.8 19.2 18.6 --   MITSuME-Akeno       
GL030402+313951 46.0087 31.6642 361.1585 19.1 19.1 18.3 --   MITSuME-Akeno      

Kanata-HONIR: 150 cm Kanata telescope at Higashi-Hiroshima Observatory and HONIR -- a 2 channel imager (Rc and H or J) (Akitaya et al. 2014, Proc. SPIE 9147, 91474O)
Nayuta-NIC: 200 cm Nayuta telescope at Nishi-Harima Astronomical Observatory and Nishiharima Infrared Camera, NIC (J, H, Ks)
OAOWFC: 91 cm Okayama Astrophysical Observatory NIR Wide Field Camera, OAOWFC (J) (Yanagisawa et al., 2019, PASJ, 71, 118
MITSuME-Akeno: 50 cm MITSuME telescope at Akeno Observatory and a 3 color imager (g, Rc, Ic)

GCN Circular 27067

Subject
LIGO/Virgo S200213t: No Counterparts from GECKO observation of host galaxy candidates in GW-neutrino detection overlap area
Date
2020-02-14T10:32:59Z (5 years ago)
From
Gregory SungHak Paek at SNU <shpaek@astro.snu.ac.kr>
Gregory S.H. Paek (SNU), Myungshin Im (SNU), Hyun-Il Sung (KASI), Gu Lim
(SNU), Joonho Kim (SNU), Sungyong Hwang (SNU), Bomi Park (SNU), Sophia Kim
(SNU), Changsu Choi (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Hyung
Mok Lee (KASI), on behalf of GECKO team

 We observed 4 host galaxy candidates with the 1.0-m telescope at the
Lemonsan Optical Astronomical Observatory(LOAO) in the initial localization
area of S200213t (Singer et al, GCN #27042) overlapped with neutrino
detection area (Hussain et al, GCN #27043).

The observation started at 2020-02-14 02:37:28 UT, 0.94 days after GW
trigger and each image was taken in R-band with 30 minutes exposure time.
No obvious transient has been identified. The list of the inspected targets
is given below.

NAME                   DISTANCE[Mpc] DATE-OBS                FILTER UL[AB]
---------------------- ------------- ----------------------- ------ -------
PGC11312               169           2020-02-14T02:37:28.000      R  21.676
2MASS+03012583+3135093 254           2020-02-14T03:15:37.333      R  21.626
UGC02483               92            2020-02-14T04:04:08.933      R  21.511
2MASS+03014097+3153413 97            2020-02-14T04:43:56.667      R  21.163

We thank the LOAO opertator for performing the observation.

Gravitational-wave EM Counterpart Korean Observatory (GECKO) is a network
of 10+ 0.5m to 1m class telescopes over the world.

GCN Circular 27068

Subject
LIGO/Virgo S200213t: One additional candidate from the Zwicky Transient Facility
Date
2020-02-14T14:00:24Z (5 years ago)
From
Simeon Reusch at DESY <simeon.reusch@desy.de>
*

Simeon Reusch (DESY), Robert Stein (DESY), Daniel Perley (LJMU),
Shreya Anand (Caltech)


On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of
Observatories Watching Transients Happen (GROWTH) collaborations:��


We observed the localization region of LIGO/Virgo S200213t with the
Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera
(Bellm et al. 2019, Graham et al. 2019). We started observations in the
g- and r-band beginning at 2020-02-13T04:34:34.500 UTC, approximately
0.4 hours after event time. We covered 78.5% of the enclosed probability
based on the map in 1999.2 sq deg. This estimate accounts for chip gaps.
Each exposure was 30s with a typical depth of 20.5 mag.��

��

The images were processed in real-time through the ZTF reduction and
image subtraction pipelines at IPAC to search for potential counterparts
(Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to search the
alerts database for candidates. We reject stellar sources (Tachibana and
Miller 2018) and moving objects, apply machine learning algorithms
(Mahabal et al. 2019), and remove candidates with history of variability
prior to the merger time. We are left with the following additional
high-significance transient candidate by our pipeline, lying within the
95.0% localization of the skymap.��


+---------------------------------------------------------------------------------+
| ZTF Name �� �� | IAU Name   | RA (deg)�� �� | DEC (deg)   | Filter | Mag �� | MagErr |
+---------------------------------------------------------------------------------+����
| ZTF20aanakcd | AT 2020cmr | 008.1570525 | +41.3157344 | r�� �� �� | 20.59 | 0.13   |
+---------------------------------------------------------------------------------+


ZTF20aanakcd (AT 2020cmr) has a host with an estimated photometric
redshift of 0.05 +/- 0.03, derived using ANNz2 (Sadeh et. al., 2015)
based on photometry from the Pan-STARRS survey (Chambers et. al., 2019).
This redshift is compatible with the reported GW distance. We caution
that this value is only a preliminary estimate.


We encourage photometric and spectroscopic follow-up to classify this
additional candidate.


ZTF and GROWTH are worldwide collaborations comprising Caltech, USA;
IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA;
DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech,
Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd,
Australia.

ZTF acknowledges the generous support of the NSF under AST MSIP Grant No
1440341.��

GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.

Alert distribution service provided by DIRAC@UW (Patterson et al. 2019).

Alert database searches are done by AMPEL (Nordin et al. 2019).

*

[GCN OPS NOTE(04feb20): Per author's request, in the author list,
Perley's affiliation was corrected from "Caltech" to "LJMU".]

GCN Circular 27069

Subject
LIGO/Virgo S200213t: No notable candidates in GOTO imaging
Date
2020-02-14T14:10:41Z (5 years ago)
From
Ben Gompertz at U of Warwick <b.gompertz@warwick.ac.uk>
R.Cutter (1); K.Ackley (2); B.P.Gompertz (1); J.Lyman (1);�� G.Ramsay 
(5); K.Ulaczyk (1); D.K.Galloway (2); E.Stanway (1); T.Killestein(1); 
K.Wiersema (1); M.Kennedy (10); D.Steeghs (1); M.Dyer (3); V.Dhillon 
(3); P.O'Brien (4); D.Pollacco (1); E.Thrane (2);S.Poshyachinda (6); 
S.Mattila (7); L.Nuttall (8); E.Palle (9); A.Levan (1); T.Marsh (1); 
R.West (1); Y.-L.Mong (2); A.Casey (2); M.Brown(2); B.Muller (2); 
J.Mullaney (3); E.Daw (3); S.Littlefair (3); J.Maund (3); L.Makrygianni 
(3); R.Starling (4); R.Eyles (4); S.Tooke(4); S.Aukkaravittayapun (6); 
U.Sawangwit (6); S.Awiphan (6); D.Mkrtichian (6); P.Irawati (6); R.Kotak 
(7); T.Heikkila (7); E.Rol (2)

(1) Warwick University, (2) Monash University, (3) University of 
Sheffield, (4) University of Leicester, (5) Armagh Observatory & 
Planetarium, (6) National Astronomical Research Institute of Thailand, 
(7) University of Turku, (8) University of Portsmouth, (9) Instituto de 
Astrofisica de Canarias), (10) Univ. of Manchester.

report on behalf of the GOTO collaboration:

We report on optical observations with the Gravitational-wave Optical 
Transient Observer prototype in response to S200213t (GCN #27042). 
Targeted observations started shortly after the preliminary event 
notification was received. These spanned 47 unique tile pointings, with 
image subtraction, containing 54.2% of the source location probability 
(based on the initial BAYESTAR skymap) and were acquired between 04:15 
UT Feb 13 2020 and 06:44 UT Feb 14 2020 (starting 3 minutes after the 
event trigger). No new transients that could be credibly associated with 
S200213t were detected.

Each pointing spans 4.9x3.7 square degrees and consisted of 3x60s 
exposures in our L-band filter (400-700nm passband similar to g+r) with 
a median 5-sigma photometric depth equivalent to g=18.4 for an 
individual pointing (median moon illumination of 71.7% and some variable 
cloud coverage was present). Limits are based on a photometric 
calibration against PS1 sources. Most pointings were observed multiple 
times, typically 2-3 times.

Images are processed immediately after acquisition using the GOTOphoto 
pipeline. Difference imaging was performed on the median of each triplet 
of exposures using recent survey observations of the same pointings. 
Source candidates were initially filtered using a classifier and 
cross-matched against a variety of catalogs, including the MPC and PS1. 
Human candidate vetting was performed following data acquisition and 
automated classifier cuts.

GOTO is operated at the La Palma observing facilities of the University 
of Warwick on behalf of a consortium including the University of 
Warwick, Monash University, Armagh Observatory, the University of 
Leicester, the University of Sheffield, the National Astronomical 
Research Institute of Thailand (NARIT), The University of Portsmouth, 
the University of Turku and the Instituto de Astrofisica de Canarias 
(IAC) (https://goto-observatory.org/)

GCN Circular 27070

Subject
LIGO/Virgo S200213t: No counterpart candidates from Nanshan-0.6m observations
Date
2020-02-14T18:53:26Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
D. Xu, Z.P. Zhu, X. Liu, B.Y. Yu, H.J. Wang, L. Ge, C.Z. Cui, Y.F. Xu, 
T.M. Zhang, X. Zhou,  (NAOC), X. Gao (Urumqi No.1 Senior High School), 
S. Yang (Stockholm U.), H.B. Zhao, B. Li (PMO), J.Z. Liu, X. Zhang 
(XAO), J.R. Mao (YNAO) report on behalf of the GWFUNC collaboration:

In the night of 2020-02-13, we first observed the 16 NED galaxy fields 
of LIGO/Virgo S200213t (GCN #27042) + IceCube neutrino candidate (GCN 
#27043), as reported in GCN #27047, using the NEXT 0.6m optical 
telescope, located at Nanshan, Xinjiang, China. Observations started at 
13:19:16 UT and ended at 14:27:36 UT in the Sloan r-filter, and each 
field was imaged twice with 90 sec for each exposure. Typical limiting 
magnitude is r~19.0.

Subsequently we observed 120 GLADE galaxy fields that are selected 
according to the probability skymap of LIGO/Virgo S200213t, the galaxy 
distance within the 3sigma limit, the B-band absolute magnitude for the 
galaxy < -18, as well as the observable altitude > ~20 deg. Observations 
were again taken in the Sloan r-filter, with 90 sec for each exposure. 
Typical limiting magnitude is r~19.0.

The list of the observed galaxies is given below.

Galaxy_Name                     R.A.(deg)  Dec.(deg)  Dist(Mpc)    M_B
GL00410559+5020596	10.27333	50.34990	295.58	-20.30
GL01133253+5515015	18.38556	55.25044	288.89	-19.91
GL01034582+5730374	15.94093	57.51041	303.28	-20.28
GL01212232+5912170	20.34303	59.20474	234.82	-19.26
GL01060074+5732009	16.50312	57.53359	145.83	-20.30
GL00575274+4850369	14.46978	48.84361	251.04	-20.20
GL01242568+5912446	21.10700	59.21240	264.02	-20.55
GL00461573+5130239	11.56556	51.50666	287.05	-20.65
GL01174717+5159283	19.44656	51.99122	315.92	-20.53
GL01281451+5910375	22.06049	59.17711	120.19	-19.63
GL01230059+5512035	20.75249	55.20097	323.84	-20.41
GL01125842+5730428	18.24345	57.51190	215.37	-19.81
GL01143751+5725468	18.65629	57.42967	358.31	-20.85
GL00342296+4948170	8.59568	49.80473	66.74        -18.56
GL00530055+5020315	13.25232	50.34211	79.53	        -19.45
GL01273606+5515383	21.90027	55.26065	80.67	        -18.99
GL00592237+5131224	14.84322	51.52291	130.21	-18.04
GL01204709+5725326	20.19623	57.42573	281.89	-21.01
GL01384386+5911064	24.68276	59.18513	310.01	-20.87
GL00583640+5027498	14.65167	50.46384	289.90	-21.02
GL00331360+4645013	8.30671	46.75037	207.42	-19.70
GL01172389+6056245	19.34955	60.94017	324.08	-20.13
GL01011268+5027319	15.30283	50.45887	186.99	-20.50
GL01110139+5220280	17.75580	52.34112	327.98	-20.33
GL01344735+5157212	23.69732	51.95591	229.92	-19.98
GL01101769+5125501	17.57371	51.43060	246.46	-19.51
GL00475975+4948595	11.99897	49.81654	148.94	-20.17
GL01421791+5513022	25.57464	55.21729	205.59	-20.96
GL01433282+5510459	25.88677	55.17944	380.55	-20.50
GL01442052+5508501	26.08553	55.14726	284.44	-20.90
GL01183234+5551083	19.63478	55.85233	119.99	-19.91
GL00430939+4648314	10.78914	46.80874	299.44	-20.89
GL00435971+4648338	10.99882	46.80940	236.67	-20.77
GL00444381+4644478	11.18258	46.74663	211.81	-19.87
GL01184793+5127462	19.69974	51.46285	143.83	-20.29
GL01422918+5730133	25.62161	57.50372	107.60	-19.67
GL01144438+5027094	18.68492	50.45263	128.25	-18.68
GL00434180+5226314	10.92417	52.44206	151.92	-18.56
GL01172570+5022512	19.35710	50.38090	97.30	        -20.33
GL01252822+5130299	21.36761	51.50833	352.84	-20.49
GL00502343+5444363	12.59766	54.74343	93.31  	-19.30
GL00542554+4642347	13.60642	46.70965	176.06	-20.20
GL01540363+5728127	28.51515	57.47021	424.54	-20.79
GL00395816+4534239	9.99235	45.57333	213.80	-20.22
GL01213941+5315288	20.41425	53.25800	267.61	-21.55
GL01223711+5314207	20.65466	53.23909	136.21	-20.26
GL00410855+5316416	10.28565	53.27823	270.03	-19.76
GL00542451+5123343	13.60215	51.39287	104.03	-19.93
GL01294222+5023095	22.42590	50.38596	89.33 	-19.86
GL01122684+4949445	18.11187	49.82903	152.31	-20.34
GL01274813+5321445	21.95057	53.36239	339.92	-21.17
GL02004334+6059449	30.18060	60.99581	208.30	-21.30
GL01161034+4952100	19.04309	49.86946	301.02	-20.88
GL01052909+5224528	16.37125	52.41468	263.13	-20.53
GL01341630+5320302	23.56792	53.34174	169.84	-19.15
GL01082772+5222341	17.11551	52.37615	336.11	-20.44
GL01211814+4948037	20.32559	49.80104	315.85	-20.59
GL01372343+5317515	24.34764	53.29766	285.73	-19.61
GL01175368+5432325	19.47367	54.54237	215.24	-19.89
GL01131402+5226144	18.30846	52.43736	128.30	-20.23
GL01150037+5225564	18.75156	52.43236	112.42	-19.50
GL01434654+5316206	25.94392	53.27240	261.11	-21.47
GL00583960+5002425	14.66503	50.04516	85.01	        -20.69
GL01003319+5241549	15.13831	52.69859	267.84	-20.76
GL01221529+5224550	20.56373	52.41530	312.19	-21.23
GL01243181+5223493	21.13257	52.39705	324.90	-20.01
GL01252477+5222580	21.35322	52.38278	302.65	-20.54
GL01073402+5359379	16.89176	53.99387	304.19	-19.99
GL00562909+5224271	14.12124	52.40754	103.75	-18.63
GL00591838+5016187	14.82662	50.27186	131.54	-20.12
GL01305475+5412455	22.72814	54.21266	297.88	-20.38
GL01330184+5224545	23.25767	52.41515	257.42	-20.52
GL01245620+5432186	21.23418	54.53851	105.89	-20.52
GL01015265+5924475	15.46940	59.41321	184.57	-20.26
GL01050655+5929246	16.27733	59.49019	315.56	-20.42
GL01014789+5128138	15.44956	51.47051	261.00	-19.91
GL01115172+5928373	17.96553	59.47705	307.34	-20.45
GL00511775+5611426	12.82399	56.19517	295.41	-20.23
GL00530999+5615243	13.29166	56.25677	316.08	-20.37
GL01291424+5158552	22.30934	51.98203	318.34	-20.52
GL01281694+5929022	22.07060	59.48396	298.37	-19.92
GL01121331+5955414	18.05550	59.92818	291.49	-19.69
GL01262972+5923369	21.62386	59.39361	373.13	-20.53
GL01032872+5614324	15.86970	56.24234	180.66	-20.20
GL01423598+5417334	25.64994	54.29261	141.80	-20.87
GL01432226+5930019	25.84275	59.50054	328.61	-20.72
GL01040289+5919003	16.01205	59.31678	170.74	-19.38
GL01470616+5931206	26.77569	59.52240	113.26	-18.17
GL01561522+5932363	29.06344	59.54342	319.31	-20.48
GL01583167+5925229	29.63198	59.42304	305.33	-19.85
GL01412969+5612438	25.37374	56.21217	261.90	-19.35
GL01431008+5446598	25.79203	54.78328	330.75	-20.91
GL01502384+5613049	27.59936	56.21803	189.20	-20.09
GL01215887+5538133	20.49532	55.63703	96.39	        -19.16
GL01134004+6031353	18.41686	60.52649	91.70 	-19.07
GL01310388+5532096	22.76619	55.53601	195.38	-19.31
GL01313530+5534046	22.89710	55.56794	175.54	-19.30
GL01325027+5535520	23.20946	55.59779	159.76	-19.26
GL01231913+6029355	20.82972	60.49321	239.39	-19.72
GL01370732+5534325	24.28054	55.57571	249.07	-19.81
GL01384099+5534414	24.67079	55.57819	274.65	-20.88
GL01471291+5707276	26.80382	57.12435	381.46	-20.34
GL01405953+6021130	25.24806	60.35363	217.79	-20.11
GL01440860+5946120	26.03584	59.77003	215.23	-19.92
GL01451454+5949020	26.31060	59.81725	294.78	-20.34
GL01194420+6043069	19.93419	60.71859	259.04	-20.36
GL01383197+5652414	24.63321	56.87819	202.71	-19.02
GL01524731+5655069	28.19713	56.91860	301.75	-21.16
GL01575361+5843286	29.47340	58.72464	155.53	-20.85
GL01470751+5914576	26.78132	59.24934	297.45	-20.38
GL01344887+6043329	23.70365	60.72583	92.39	        -18.87
GL01531807+5915358	28.32532	59.25997	119.58	-20.78
GL01525926+5834286	28.24694	58.57464	204.72	-19.25
GL01554543+5822323	28.93932	58.37565	295.40	-20.61
GL01574657+5829567	29.44406	58.49910	386.86	-20.12
GL01532514+5812179	28.35478	58.20497	383.78	-20.43
GL01511041+5841163	27.79341	58.68787	408.56	-19.80
GL01590512+5843327	29.77135	58.72576	325.94	-20.08
GL01543478+5752397	28.64494	57.87772	310.87	-20.38
GL01580404+5858448	29.51685	58.97912	406.74	-20.55

Preliminary analysis doesn't reveal any credible optical counterpart in 
all the above galaxies. Full analysis is still ongoing.

GCN Circular 27071

Subject
LIGO/Virgo S200213t: Upper limits from Insight-HXMT/HE observations
Date
2020-02-14T19:13:12Z (5 years ago)
From
YaoGuang Zheng at IHEP <zhengyg@ihep.ac.cn>
Y. G. Zheng, C. Cai, Y. F. Du, W. C. Xue, 
Q. Luo, S. Xiao, Q. B. Yi, Y. Huang, C. K. Li, G. Li, 
X. B. Li, J. Y. Liao, S. L. Xiong,C. Z. Liu, 
X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, 
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), 
T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

Insight-HXMT was taking data normally around the reported LIGO/Virgo 
S200213t event (GCN #27042), trigger time 2020-02-13T04:10:40.328 UTC. 
At T0, about 13% of the LIGO localization region was covered by the 
Insight-HXMT without occultationby the Earth.

Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are 
found in a search of the Insight-HXMT/HE raw light curves.

Assuming the GW counterpart GRB with three typical GRB Band spectral 
models, two typical duration timescales (1 s, 10 s) from the center 
of the LIGO-Virgo location probability map (RA=325.95 deg, DEC=-13.64 deg), 
the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are 
reported below:

Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV):
1 s:   3.9e-07 erg cm^-2
10 s:  1.0e-06 erg cm^-2

Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV):
1 s:   6.0e-07 erg cm^-2
10 s:  1.8e-06 erg cm^-2

Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV):
1 s:   9.6e-07 erg cm^-2
10 s:  2.9e-06 erg cm^-2

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (deposited energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the spacecraft.

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information could be found at: http://www.hxmt.org.

GCN Circular 27072

Subject
LIGO/Virgo S200213t: MASTER OT detection in PGC673735
Date
2020-02-14T21:09:13Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov,  P.Balanutsa, E. Gorbovskoy, V.Kornilov, N.Tyurina, A.Kuznetsov,F.Balakin, K.Zhirkov,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, 
A.Chasovnikov, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University)
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),

MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
covered 1376 square degrees of S299213t (LVC GCN 27042, Lipunov et al. GCN 27041,
https://gcn.gsfc.nasa.gov/other/S200213t.gcn3)
that is equal to 100% of 50%-error-field and 79% of 90%-error-field
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11331


  MASTER OT J095359.98-333736.2 discovery - PSN in 3.3"E,0.7"N of PGC673735

MASTER-SAAO auto-detection system discovered OT source at
(RA, Dec) = 09h 53m 59.98s -33d 37m 36.2s on 2020-02-11.78015 UT.

The OT unfiltered magnitude is 19.0m (mlim=19.7).

The OT is seen in both 2 inspect images. There is no minor planet at this place.

We have reference image on 2015-01-23.98993 UT with unfiltered mlim= 19.9m.

Spectral observations are required.

The discovery and reference images are available at:

Observations and  analysys will be continued.
The message may be cited.

GCN Circular 27074

Subject
LIGO/Virgo S200213t: DBSP spectroscopy of AT2020cjb/ZTF20aamvnth, AT2020cja/ZTF20aamvmzj, AT2020cjc/ZTF20aamvoeh
Date
2020-02-15T02:17:15Z (5 years ago)
From
Anna Ho at Caltech <annayqho@gmail.com>
Anna Y. Q. Ho and Andy Tzanidakis (Caltech) report on behalf of the GROWTH
collaboration:

On 2020-02-14 UT we obtained spectroscopy of three of the reported ZTF
optical transients (Kasliwal et al. GCN 27051) inside the error region of
S200213t (LVC,GCN #27042) using the Double Beam Spectrograph on the
200-inch Hale Telescope at Palomar Observatory. We used SNID to make
preliminary classifications.

The spectrum of AT2020cjb/ZTF20aamvnth shows a broad emission feature
consistent with H-alpha at the host redshift of z=0.06, corroborating the
SN II classification reported in Castro-Tirado et al. GCN #27063.

The spectrum of AT2020cjc/ZTF20aamvoeh is a match to a type Ia SN at z~0.14
close to maximum light.

The spectrum of AT2020cja/ZTF20aamvmzj has a blue continuum and a broad
emission feature around 5600AA.

Observations of additional sources are ongoing.

GCN Circular 27075

Subject
LIGO/Virgo S200213t: P200 Spectroscopy of ZTF20aanakcd/AT2020cmr
Date
2020-02-15T06:23:56Z (5 years ago)
From
Igor Andreoni at Caltech <igor.andreoni@gmail.com>
Igor Andreoni (Caltech), Kishalay De (Caltech), Mansi Kasliwal (Caltech), Yang Huang (Yunnan Univ.), Xiaowei Liu (Yunnan Univ.)
On behalf of the GROWTH collaboration

On 2020-02-15 03:30 UT, we used the Double Beam Spectrograph (Oke & Gunn 1982) on the Palomar 200-inch telescope to observe ZTF20aanakcd/AT2020cmr (Reusch et al., GCN #27068), a transient discovered with the Zwicky Transient Facility (Graham et al., 2019; Bellm et al., 2019) during the follow-up of the binary neutron star merger candidate S200213t (LVC, GCN #2704).

The optical spectrum shows intermediate width Balmer emission features consistent with a Type IIn supernova at z=0.077. We also confirmed that the redshift of the transient is consistent with the host galaxy redshift, extracted from the same observations, based on the analysis of Balmer and [S II] lines.  We conclude that ZTF20aanakcd/AT2020cmr is unrelated to S200213t.

GCN Circular 27076

Subject
LIGO/Virgo S200213t: No neutrino candidates at Pierre Auger Observatory
Date
2020-02-15T10:16:25Z (5 years ago)
From
Jaime Alvarez-Muniz at Pierre Auger Observatory <jaime.alvarezmuniz@gmail.com>
J. Alvarez-Muniz, F. Pedreira, E. Zas (IGFAE & University of Santiago de
Compostela, Spain),
K. H. Kampert & M. Schimp (University of Wuppertal, Germany)
on behalf of the Pierre Auger Collaboration.

In response to:
LIGO/Virgo GW trigger S200213t
T0=2020-02-13  04:10:40 UTC

We searched for Ultra-High-Energy (UHE) neutrinos with energies
above ~ 1e17 eV in data collected with the Surface Detector (SD)
of the Pierre Auger Observatory in a [-500,500] second interval
about the LIGO-Virgo trigger S200213t as well as in a 24 hr time
interval following the event.

NO events survived the cuts applied to reject the background due
to UHE Cosmic Rays i.e. NO neutrino candidates were detected.

The field of view (fov) where the SD of Auger is sensitive to UHE
neutrinos (corresponding to inclined directions with respect to the
vertical relative to the ground) was PARTIALLY COINCIDENT (19.8%)
at the time T0 of the merger alert, with the latest LIGO/Virgo 90%
localization region (bayestar.fits.gz), achieving a MAXIMUM OVERLAP
(66.5%) at approximately T0+14.06 hours.

-------
The Pierre Auger Observatory is an UHE Cosmic Ray detector
located in the Mendoza Province in Argentina. It consists of
an array of Water Cherenkov detectors spread over a total surface
of 3000 km^2 arranged in a triangular grid of 1.5 km side as well
as Fluorescence telescopes and other systems
(see 10.1016/j.nima.2015.06.058 for more information).
For neutrino searches with Auger, please refer to:
https://iopscience.iop.org/article/10.1088/1475-7516/2019/10/022
https://iopscience.iop.org/article/10.1088/1475-7516/2019/11/004

GCN Circular 27077

Subject
LIGO/Virgo S200213t: MASTER possible Kilonova candidate in PGC315337
Date
2020-02-15T14:47:28Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov,  V.Shumkov, E. Gorbovskoy, V.Kornilov, P.Balanutsa, N.Tyurina, V.Vladimirov, A.Kuznetsov,
F.Balakin, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
A.Chasovnikov, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University)
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),

MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
covered 1525 square degrees of S299213t (LVC GCN 27042, Lipunov et al. GCN 27041, GCN 27072
https://gcn.gsfc.nasa.gov/other/S200213t.gcn3 )
that is equal to 100% of 50%-error-field and 81% of 90%-error-field
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11331

MASTER OT J044008.76-651302.3 discovery - OT in 15"W,39.5"S from PGC315337 center (in 3-sigma of LVC error-box)
AT2020cph

MASTER-SAAO auto-detection system  discovered OT source at
R.A.,Dec(2000) = 04h 40m 08.76s -65d 13m 02.3s on 2020-02-14.91294 UT.

The OT unfiltered magnitude (automatic photometry):
2020-02-13 22:03:33UT     19.6
2020-02-14 02:11:16UT     19.0
2020-02-14 22:04:43UT     18.9

We have reference image on 2017-12-22.95279 UT with  unfiltered mlim= 20.3m, nearest in time at
2020-01-27 20:13:33 with mlim=19.0

Spectral observations are required.

PGC315337 has Btc=16.2 (no V in LEDA)

Observations and  analysys will be continued.
The message may be cited.

GCN Circular 27082

Subject
LIGO/Virgo S200213t: Lulin Follow-Up Observations
Date
2020-02-15T17:18:22Z (5 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
K.L. Li, A.K.H. Kong (NTHU), C.-C. Ngeow, H.-J. Tan, W.-H. Ip (NCU)

On behalf of the Global Relay of Observatories Watching Transients
Happen (GROWTH) collaborations

From 2020-02-14 11:03:25 to 2020-02-14 13:08:23 UT, we used the Lulin
One-meter Telescope (LOT) at Lulin Observatory, Taiwan to follow up
five candidate electromagnetic counterparts (GCN #27051, #27065) of
the LIGO/Virgo event S200213t (GCN #27042). For each target, g'-, r'-,
and i'-band imaging data were taken (240 sec for each band). Here are
the summary of the result. Preliminary photometry (AB) was obtained by
calibrating with the PS1 catalogue.

AT2020cja: g=20.37+/-0.10, r=20.58+/-0.14, i=21.02+/-0.51
AT2020cls: g>18.9, r=21.12+/-0.32, i=20.97+/-0.37
AT2020clt: g=21.47+/-0.24, r=19.34+/-0.04, i=19.98+/-0.12 (the result
may be unreliable because of the host background)
AT2020clu: g=20.80+/-0.14, r=20.79+/-0.15, i=21.19+/-0.47
AT2020clw: g=21.46+/-0.42, r=21.09+/-0.22,i=20.75+/-0.37

We thank the support from the Lulin team for our ToO request.

GCN Circular 27084

Subject
LIGO/Virgo S200213t: No transient candidates in CALET observations
Date
2020-02-15T18:46:44Z (5 years ago)
From
Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), 
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, 
T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger 
time of S200213t T0 = 2020-02-13 04:10:40.328 UT (The LIGO Scientific 
Collaboration and Virgo Collaboration, GCN Circ. 27042).

No CGBM on-board trigger occurred around the event time.  Based on the
LVC high probability localization region, the summed LIGO probabilities
inside the CGBM HXM (7 - 3000 keV) and SGM (40 keV - 28 MeV) fields
of view are 2 % and 12 %, respectively (and 31 % credible region of the
updated localization map was above the horizon).  The HXM and SGM fields
of view were centered at RA = 108.0 deg, Dec = -27.8 deg and 
RA = 101.3 deg, Dec = -36.1 deg at T0, respectively.

Based on the analysis of the light curve data with 0.125 sec time 
resolution from T0-60 sec to T0+60 sec, we found no significant excess
(signal-to-noise ratio >= 7) around the trigger time in either the HXM or
the SGM data.

The CALET Calorimeter (CAL) was operating in the high energy trigger
mode at the trigger time of S200213t. Using the CAL data, we have
searched for gamma-ray events in the 10-100 GeV band from -60 sec
to +60 sec from the GW trigger time and found no candidates. There 
was no significant overlap with the LVC high probability localization 
region at T0+-60 sec. The CAL FOV was centered at RA = 101.4 deg,
Dec = -36.1 deg at T0.

GCN Circular 27085

Subject
LIGO/Virgo S200213t: Pre-discovery detections of MASTER OT J044008.76-651302.3
Date
2020-02-15T19:23:48Z (5 years ago)
From
Przemek Mroz at Warsaw U. Observatory <pmroz@astrouw.edu.pl>
Przemek Mroz (Caltech), Mariusz Gromadzki (Warsaw), Andrzej Udalski
(Warsaw), on behalf of the OGLE team:

MASTER OT J044008.76-651302.3 (GCN 27077) is located in the field LMC542
that is regularly observed by the <a
href="http://ogle.astrouw.edu.pl/">OGLE</a>
survey (Udalski et al. 2015). The object was detected on images taken on
2020-02-04 and 2020-02-12, before the LIGO/Virgo trigger. It is therefore
unrelated to S200213t.

I-band magnitudes:

2020-02-04 03:29:43UT 19.61
2020-02-12 01:53:19UT 18.91

GCN Circular 27092

Subject
LIGO/Virgo S200213t: Updated Sky Localization
Date
2020-02-16T02:34:18Z (5 years ago)
From
Leo Singer at GSFC <leo.p.singer@nasa.gov>
The LIGO Scientific Collaboration and the Virgo Collaboration report:

We have conducted further analysis of the LIGO Hanford Observatory
(H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data
around the time of the compact binary merger (CBC) candidate S200213t
(GCN Circular 27042). Parameter estimation has been performed using
Bilby [1] and a new sky map, bilby.fits.gz,0, distributed via GCN
Notice, is available for retrieval from the GraceDB event page:

https://gracedb.ligo.org/superevents/S200213t

The preferred sky map at this time is bilby.fits.gz,0. For the
bilby.fits.gz,0 sky map, the 90% credible region is 282 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 141 +/- 56 Mpc (a posteriori mean +/- standard deviation).

For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.

[1] Ashton et al. ApJS 241, 27 (2019)

GCN Circular 27093

Subject
LIGO/Virgo S200213t: Possible host galaxies in the bilby skymap
Date
2020-02-16T02:56:43Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester) reports,

The bilby.fits.gz,0 GW skymap has been convolved with the 2MPZ galaxy catalogue (Bilicki et al., ApJS, 210, 9),
using the method described in Evans et al (2016, MNRAS, 462, 1591*), to identify
a ranked list of potential host galaxies of the LVC trigger S200213t. This galaxy ranking
method accounts for the (line-of-sight dependent) completeness of 2MPZ, GW probability,
and the overlap between P(D) functions for the GW event and the individual galaxies.

In total 4040 galaxies with P>10^-5 have been identified. The most probable 20 are listed below,
a full list and more details are available at https://www.swift.ac.uk/LVC/S200213t/galaxies


|               Galaxy name |   P_host |             RA |            Dec | K_mag |      GalDist |
--------------------------------------------------------------------------------------------------
|    2MPZ J01154286+5559475 | 8.01e-03 | 01h 15m 42.86s | +55d 59' 47.4" | 10.9 | 172.1 +/- 7.4 |
|    2MPZ J01215577+5601372 | 7.31e-03 | 01h 21m 55.78s | +56d 01' 37.2" | 11.0 | 179.3 +/- 7.4 |
|    2MPZ J00585413+5236357 | 7.22e-03 | 00h 58m 54.14s | +52d 36' 35.6" | 10.4 | 135.4 +/- 7.4 |
|    2MPZ J00402207+4141070 | 6.41e-03 | 00h 40m 22.08s | +41d 41' 07.1" | 5.7 | 61.1 +/- 42.9 |
|    2MPZ J01161702+5352580 | 6.07e-03 | 01h 16m 17.02s | +53d 52' 58.1" | 11.3 | 197.7 +/- 7.4 |
|    2MPZ J01183038+5156442 | 5.67e-03 | 01h 18m 30.38s | +51d 56' 44.2" | 9.7 | 124.3 +/- 7.4 |
|    2MPZ J00592750+5222015 | 5.65e-03 | 00h 59m 27.50s | +52d 22' 01.6" | 11.2 | 163.7 +/- 7.4 |
|    2MPZ J00585906+5238557 | 5.48e-03 | 00h 58m 59.06s | +52d 38' 55.7" | 10.6 | 129.6 +/- 7.4 |
|    2MPZ J00513895+5205260 | 4.64e-03 | 00h 51m 38.95s | +52d 05' 26.2" | 9.9 | 116.3 +/- 7.4 |
|    2MPZ J01192705+5831151 | 4.44e-03 | 01h 19m 27.05s | +58d 31' 15.2" | 10.0 | 151.8 +/- 47.9 |
|    2MPZ J01311381+5545126 | 4.12e-03 | 01h 31m 13.82s | +55d 45' 12.6" | 10.7 | 160.6 +/- 7.4 |
|    2MPZ J00544651+5108434 | 4.03e-03 | 00h 54m 46.51s | +51d 08' 43.4" | 11.2 | 196.5 +/- 7.4 |
|    2MPZ J01014603+5556556 | 4.00e-03 | 01h 01m 46.03s | +55d 56' 55.7" | 10.8 | 177.0 +/- 7.4 |
|    2MPZ J01291379+5600241 | 3.92e-03 | 01h 29m 13.80s | +56d 00' 24.1" | 11.2 | 172.4 +/- 7.4 |
|    2MPZ J01033453+5225416 | 3.89e-03 | 01h 03m 34.54s | +52d 25' 41.5" | 11.4 | 141.8 +/- 7.4 |
|    2MPZ J01025660+5120324 | 3.82e-03 | 01h 02m 56.62s | +51d 20' 32.6" | 10.3 | 111.8 +/- 7.4 |
|    2MPZ J01022406+5214345 | 3.80e-03 | 01h 02m 24.07s | +52d 14' 34.4" | 11.2 | 135.3 +/- 7.4 |
|    2MPZ J01313530+5534046 | 3.64e-03 | 01h 31m 35.30s | +55d 34' 04.8" | 10.9 | 172.6 +/- 7.4 |
|    2MPZ J00110106+3003072 | 3.39e-03 |  00h 11m 1.06s | +30d 03' 07.2" | 10.0 | 98.7 +/- 7.4 |
|    2MPZ J00583689+5137088 | 3.34e-03 | 00h 58m 36.89s | +51d 37' 08.8" | 10.4 | 111.2 +/- 7.4 |
--------------------------------------------------------------------------------------------------

(* See also the erratum: MNRAS, 484, 2362; or arXiv 1606.05001 for the full manuscript with erratum applied).

GCN Circular 27094

Subject
LIGO/Virgo S200213t: CLU/NED Galaxies in the 4-Update Localization Volume
Date
2020-02-16T03:10:36Z (5 years ago)
From
David Cook at IPAC/Caltech <dcook@ipac.caltech.edu>
David O. Cook (Caltech/IPAC), Angela Van Sistine (UW Milwaukee), Leo Singer (NASA/GSFC), Igor Andreoni (Caltech), Michael Coughlin (Caltech), Bob Aloisi (UW Milwaukee), Patrick R. Brady (UW Milwaukee), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), David Kaplan (UW Milwaukee), Mansi M. Kasliwal (Caltech), Joseph M. Mazzarella (Caltech/IPAC), and Marion Schmitz (Caltech/IPAC)

On behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration and the NASA/IPAC Extragalactic Database (NED) Team.

We spatially cross-matched the LIGO/Virgo S200213t trigger sky localization with the Census of the Local Universe (CLU; Cook et al. 2019) catalog and found !###! galaxies within the 90% containment volume. The CLU catalog is a compilation of galaxies with existing redshifts from many sources (e.g., NED, SDSS, etc) and new galaxies from a 3PI narrow-band survey to look for redshifted Halpha emission out to 200 Mpc with the Palomar Oschin 48-inch telescope (Cook et al. 2019).

We list here the top 20 galaxies located in the 90% volume sorted by stellar mass (Mstar). The list also contains the dust-corrected star formation rates (SFRs) for galaxies with GALEX FUV detections and a 'nan' for those with no detection.

For an extended list of galaxies in the 90% volume go to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/. This service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic followup observations. The NED top 20 list is sorted by 2MASS absolute K-band magnitude, but users can sort the entire list on a variety of other criteria (probability density, UV magnitudes, etc) after download.


          name              ra      dec   distmpc logsfr_fuv logmstar  dP_dV
------------------------ -------- ------- ------- ---------- -------- --------
           CGCG 535-012   9.0874 45.6650  198.38       1.16    11.36 3.24e-07
             AGC 333426 357.3938 32.1342   68.65        nan    11.18 1.17e-06
              UGC 00006   0.7901 21.9602  101.30       1.40    11.12 6.32e-07
         MCG +08-03-003  14.9866 47.7862  199.48        nan    11.08 1.88e-06
              UGC 00361   9.1041 49.0132  167.77        nan    11.02 6.26e-07
               NGC 0794  30.6222 18.3730  117.50      -0.78    11.01 3.11e-07
2MASX J00523155+4620186  13.1314 46.3384  199.35        nan    11.00 7.63e-07
                IC 5370   0.0383 32.7384  144.06        nan    10.99 6.69e-07
                IC 5373   0.1200 32.7824  136.15        nan    10.98 1.21e-06
                ARK 008   5.3923 38.0930  151.56       1.10    10.98 1.46e-06
2MASX J01183038+5156442  19.6267 51.9457  118.31        nan    10.97 9.53e-06
              UGC 00087   2.4433 28.3407  115.49        nan    10.95 9.10e-06
2MASX J01224216+5201127  20.6756 52.0202  198.88        nan    10.95 3.26e-06
2MASX J00484648+5609272  12.1937 56.1576  164.48        nan    10.93 3.13e-07
2MASX J01161702+5352580  19.0710 53.8828  185.89        nan    10.91 9.85e-06
              UGC 01514  30.4996 21.0965  126.17       0.08    10.90 3.45e-07
2MASX J00385452+4828030   9.7272 48.4675  169.75        nan    10.90 1.31e-06
2MASX J01155540+5103031  18.9809 51.0509  199.70        nan    10.90 2.75e-06
               V Zw 075  22.8972 55.5680  162.97        nan    10.90 5.93e-06
           CGCG 535-007   6.8912 45.5811  168.14        nan    10.89 5.50e-07


Table: Top 20 galaxies in CLU that fall in the 90% probability volume for S200213t sorted by stellar mass. Column descriptions are as follows. name: galaxy name. ra: RA (J2000, decimal degrees). dec: Dec (J2000, decimal degrees). distmpc: galaxy distance (Mpc). logsfr_fuv: log10 of the star formation rate (SFR, Msun per year), derived from GALEX All Sky Kron FUV magnitudes via the prescription of Murphy et al. (2011), corrected for internal dust extinction using a combination of GALEX FUV and 22um ALLWISE fluxes (Hao et al. 2011). logmstar: log10 of the galaxy stellar mass (Msun), estimated from 3.4um ALLWISE fluxes and a mass-to-light ratio of 0.5 (McGaugh & Schombert et al. 2015). dP_dV: the 3D probability density per cubic megaparsec at the position of each galaxy.

GCN Circular 27095

Subject
LIGO/Virgo S200213t: Updated coverage and candidate list for the Zwicky Transient Facility
Date
2020-02-16T04:38:13Z (5 years ago)
From
Igor Andreoni at Caltech <igor.andreoni@gmail.com>
Michael Coughlin (U Minn), Igor Andreoni (Caltech), Varun Bhalerao (IITB), S. Brad Cenko (NASA GSFC), Danny Goldstein (Caltech), Viraj Karambelkar (Caltech), Mansi M. Kasliwal (Caltech), Harsh Kumar (IITB), Simeon Reusch (DESY), Robert Stein (DESY)

on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations:

An updated skymap from the bilby pipeline (Ashton et al., 2019) was released for the gravitational-wave trigger S200213t (LVC, GCN #27042). We previously reported observations performed with the Palomar 48-inch telescope equipped with the Zwicky Transient Facility camera (ZTF, Bellm et al. 2019, Graham et al. 2019) in Kasliwal et al., GCN #27051. The updated ZTF coverage based on the bilby skymap is 81%.

Several candidates discovered with ZTF were previously reported (Kasliwal et al., GCN #27051; Andreoni et al., GCN #27065; Reusch et al., GCN #27068), most of which were spectroscopically classified as transients unrelated to S200213t (Valeev et al., GCN #27060; Castro-Tirado et al., GCN #27063; Ho et al., GCN #27074; Andreoni et al., GCN #27075).

Candidates that require spectroscopic follow-up and are included in the 95% probability area of the bilby skymap are listed in the table below.

+--------------+-----------+-------------+--------------+--------+------+----------+-------+
|     Name     |  IAU Name |      RA     |     Dec      | filter | mag  |   MJD    | Notes |
+--------------+-----------+-------------+--------------+--------+------+----------+-------+
| ZTF20aanakwb | AT2020cls | 00:26:05.17 | +42:46:25.40 |   g    | 21.0 | 58893.11 |       |
| ZTF20aanaltd | AT2020clt | 00:38:57.76 | +43:26:27.85 |   g    | 20.8 | 58893.11 |       |
| ZTF20aamvpvx | AT2020clx | 02:07:45.67 | +20:01:50.21 |   g    | 20.3 | 58892.21 |  (1)  |
| ZTF20aanamcs | AT2020crc | 00:54:58.40 | +43:29:52.89 |   r    | 20.9 | 58893.14 |  (2)  |
| ZTF20aanakge | AT2020crd | 00:50:31.35 | +41:29:03.04 |   r    | 20.7 | 58893.14 |       |
| ZTF20aanaqhe | AT2020cre | 01:08:10.22 | +45:31:32.37 |   g    | 20.9 | 58892.22 |  (3)  |
| ZTF20aanakes | AT2020cly | 00:08:23.65 | +38:02:38.86 |   g    | 21.1 | 58893.11 |  (a)  |
+--------------+-----------+-------------+--------------+--------+------+----------+-------+

(a) orphan, g-r~0.8, 22 minutes of time separation between detections
(1) photoz = 0.07 (SDSS)
(2) photoz = 0.13 (SDSS)
(3) photoz = 0.16 (SDSS)

ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert filtering and follow-up coordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). Alert database searches are done with using the Kowalski infrastructure (Duev et al., 2019) and with AMPEL (Nordin et al. 2019).

GCN Circular 27096

Subject
LIGO/Virgo S200213t: Updated Sky Localization
Date
2020-02-16T05:17:13Z (5 years ago)
From
Leo Singer at GSFC <leo.p.singer@nasa.gov>
The LIGO Scientific Collaboration and the Virgo Collaboration report:

We have conducted further analysis of the LIGO Hanford Observatory
(H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data
around the time of the compact binary merger (CBC) candidate S200213t
(GCN Circular 27042, 27092). Parameter estimation has been performed
using LALInference [1] and a new sky map, LALInference.fits.gz,0,
distributed via GCN Notice, is available for retrieval from the GraceDB
event page:

https://gracedb.ligo.org/superevents/S200213t

The preferred sky map at this time is LALInference.fits.gz,0. For the
LALInference.fits.gz,0 sky map, the 90% credible region is 2326 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 201 +/- 80 Mpc (a posteriori mean +/- standard deviation).

This supersedes the previous Bilby analysis (GCN Circular 27092), which
was done with an outdated estimate of detector calibration uncertainty.

For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.

 [1] Veitch et al. PRD 91, 042003 (2015)

GCN Circular 27111

Subject
LIGO/Virgo S200213t: AstroSat CZTI upper limits
Date
2020-02-17T04:42:43Z (5 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
V. Shenoy (IITB), Aarthy E. (PRL), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

We have carried a search for X-ray candidates in Astrosat CZTI data in a 100 sec window around the trigger time of the BNS Merger event S200213t (UTC 2020-02-13 04:10:40, GraceDB event). We use the LALInference.fits.gz,0 map (GCN 27096, https://gracedb.ligo.org/api/superevents/S200213t/files/LALInference.fits.gz,0) for our analysis. CZTI is a coded aperture mask instrument that has considerable effective area for about 29% of the entire sky, but is also sensitive to brighter transients from the entire sky. At the time of the merger, Astrosat's nominal pointing is RA,DEC = 04:39:16.2, -68:07:29.9 (69.8175,-68.1250), which is ~130 deg away from the maximum probability location. At the time of the merger event, the Earth-satellite-transient angle corresponding to maximum probability location is ~88 deg and hence is not occulted by Earth in satellite's frame. In a time interval of 100 sec around the event, the region of the localisation map which is not occulted by Earth in the satellite's frame has a cumulative probability of 0.97 (97%).

CZTI data were de-trended to remove orbit-wise background variation. We then searched data from the four independent, identical quadrants to look for coincident spikes in the count rates. Searches were undertaken by binning the data in 0.1s, 1s, and 10s respectively. Statistical fluctuations in background count rates were estimated by using data from 10 (+-5) neighbouring orbits. We selected confidence levels such that the probability of a false trigger in a 1000 sec window is 10^-4. We do not find any evidence for any hard X-ray transient in this window, in the CZTI energy range of 20-200 keV.

We use a detailed mass model of the satellite to calculate the direction-dependent instrument response for points in the visible sky. We then assume the source is modelled as a power law with photon index alpha = -1, and convert our count rate upper limits to direction-dependent flux limits. We obtain the following upper limits for source flux in the 20-200 keV band by taking a probability weighted mean over the visible sky:

0.1 s: flux limit= 9.77e-06 ergs/cm^2/s; fluence limit = 9.77e-07 ergs/cm^2
1.0 s: flux limit= 3.22e-06 ergs/cm^2/s; fluence limit = 3.22e-06 ergs/cm^2
10.0 s: flux limit= 4.15e-07 ergs/cm^2/s; fluence limit = 4.15e-06 ergs/cm^2

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.

GCN Circular 27116

Subject
LIGO/Virgo S200213t : No significant candidates in FRAM - OAJ - TAROT - GRANDMA observations
Date
2020-02-17T20:40:23Z (5 years ago)
From
Martin Blazek at HETH/IAA-CSIC <alf@iaa.es>
M. Blazek (HETH/IAA-CSIC), S. Agayeva (SHAO), A. Baransky (Kyiv Uni),
P. Hello (IJCLab), E. Howell (OzGrav-UWA),  (FZU), K. Bensch
(HETH/IAA-CSIC), M. Boer (Artemis), N. Christensen (Artemis), L. Eymar
  (Artemis), J. Feliciano Ag����-Fern��ndez (HETH/IAA-CSIC), L. Izzo
(HETH/IAA-CSIC), D. A. Kann (HETH/IAA-CSIC), S. Karpov (FZU), M. Prouza
(FZU), A. Klotz (IRAP), M. Masek (FZU), K. Noysena (Artemis, IRAP),
C. Thoene (HETH/IAA-CSIC), A. Ugarte Postigo (IAA/CSIC, DARK/NBI),
S. Antier (APC), A. Coleiro (APC), D. Corre (IJCLab), M. Coughlin (UMN),
D. Coward (Oz   Grav-UWA), J.G. Ducoin (IJCLab), B. Gendre (OzGrav-UWA),
N. Kochiashvili (Iliauni), C. Lachaud (APC), N. Leroy (IJCLab),
D. Turpin (AIM-CEA), X. Wang (THU)

report on behalf of the FRAM, TAROT, HETH and GRANDMA collaborations.

We performed tiled observations of LIGO/Virgo S200213t event with the
FRAM-Auger, FRAM-CTA-N, OAJ-T80, TAROT-Calern (TCA), TAROT-Chili
(TCH), TAROT-Reunion (TRE) telescopes.

FRAM-Auger is located at Pierre Auger Observatory. FRAM-CTA-N is
located at Observatorio del Roque de los Muchachos. OAJ is located at
Javalambre observatory. TCA is located at Calern site at the Cote
d'Azur observatory. TCH is located at La Silla ESO observatory
(LaS/ESO). TRE is located at Les Makes astronomical observatory.

The following table shows for each telescope: the delay in minutes
from the trigger, which filter is used, the field of view of the
telescope in degrees and the typical limiting magnitude (AB mag) for a
  given exposure in seconds (s).

+-------------+---------+----------+-------------+-------------+
| Telescope   | Delay   | Filter   | f.o.v.      | Limiting    |
|             | [min]   |          | [deg]       | Mag.        |
|-------------+---------+----------+-------------+-------------|
| FRAM-Auger  | 1220    | R        | 1.0 x 1.0   | 18.0 (60s)  |
| FRAM-CTA-N  | 932     | R        | 0.45 x 0.45 | 17.0 (90s)  |
| OAJ         | 898     | r        | 1.4 x 1.4   | 21.0 (180s) |
| TCA         | 26      | Clear    | 1.9 x 1.9   | 18.0 (60s)  |
| TCH         | 2703    | Clear    | 1.9 x 1.9   | 18.0 (60s)  |
| TRE         | 717     | Clear    | 4.2 x 4.2   | 17.0 (60s)  |
+-------------+---------+----------+-------------+-------------+

We performed the following joint tiled observations [1] :

+-------------+------------+------------+---------+---------+---------+
| Telescope   | TStart     | TEnd       | RA      | DEC     | Proba   |
|             | [UTC]      | [UTC]      | [deg]   | [deg]   | [%]     |
|-------------+------------+------------+---------+---------+---------|
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 31.705  | 18.000  | <0.1    |
|             | 00:29:55   | 00:34:22   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 31.886  | 18.973  | <0.1    |
|             | 00:34:58   | 00:39:25   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 32.914  | 18.973  | <0.1    |
|             | 00:40:00   | 00:44:27   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 35.581  | 21.892  | <0.1    |
|             | 00:45:03   | 00:49:30   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 36.416  | 20.919  | <0.1    |
|             | 00:50:06   | 00:54:33   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 33.943  | 18.973  | <0.1    |
|             | 00:55:08   | 00:59:35   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 34.971  | 18.973  | <0.1    |
|             | 01:00:11   | 01:04:38   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 32.727  | 18.000  | <0.1    |
|             | 01:05:14   | 01:09:41   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 35.376  | 20.919  | <0.1    |
|             | 01:10:16   | 01:14:43   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 31.525  | 17.027  | <0.1    |
|             | 01:15:19   | 01:19:46   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 32.542  | 17.027  | <0.1    |
|             | 01:20:23   | 01:24:50   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 35.172  | 19.946  | <0.1    |
|             | 01:25:27   | 01:29:54   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 36.628  | 21.892  | <0.1    |
|             | 01:30:31   | 01:34:58   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 28.156  | 15.081  | <0.1    |
|             | 01:35:37   | 01:40:04   |         |         |         |
| FRAM-Auger  | 2020-02-14 | 2020-02-14 | 30.168  | 15.081  | <0.1    |
|             | 01:40:41   | 01:45:08   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 16.074  | 54.837  | 0.2     |
|             | 19:41:53   | 19:45:59   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 17.005  | 55.273  | 0.2     |
|             | 19:46:14   | 19:50:20   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 19.382  | 57.021  | 0.2     |
|             | 19:50:36   | 19:54:42   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 16.829  | 54.837  | 0.2     |
|             | 19:55:02   | 19:59:08   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 18.926  | 56.147  | 0.2     |
|             | 19:59:23   | 20:03:28   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 15.009  | 53.963  | 0.2     |
|             | 20:03:44   | 20:07:50   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 18.584  | 57.021  | 0.2     |
|             | 20:08:06   | 20:12:12   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 17.584  | 54.837  | 0.2     |
|             | 20:12:27   | 20:16:33   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 15.749  | 53.963  | 0.2     |
|             | 20:16:48   | 20:20:54   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 18.147  | 56.147  | 0.2     |
|             | 20:21:10   | 20:25:16   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 16.488  | 53.963  | 0.2     |
|             | 20:25:31   | 20:29:37   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 17.368  | 56.147  | 0.2     |
|             | 20:29:51   | 20:33:57   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 16.242  | 55.273  | 0.2     |
|             | 20:34:11   | 20:38:17   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 19.706  | 56.147  | 0.2     |
|             | 20:38:38   | 20:42:44   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 16.589  | 56.147  | 0.2     |
|             | 20:42:59   | 20:47:05   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 17.767  | 55.273  | 0.2     |
|             | 20:47:19   | 20:51:24   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 17.227  | 53.963  | 0.2     |
|             | 20:51:38   | 20:55:44   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 15.319  | 54.612  | 0.2     |
|             | 20:55:59   | 21:00:05   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 18.338  | 54.837  | 0.2     |
|             | 21:00:20   | 21:04:25   |         |         |         |
| FRAM-CTA-N  | 2020-02-13 | 2020-02-13 | 18.530  | 55.273  | 0.2     |
|             | 21:04:40   | 21:08:45   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| OAJ         | 2020-02-13 | 2020-02-13 | 16.471  | 54.545  | 1.7     |
|             | 19:08:37   | 19:13:37   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 17.027  | 55.909  | 1.6     |
|             | 19:14:05   | 19:19:05   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 20.140  | 57.273  | 1.6     |
|             | 19:19:33   | 19:24:33   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 19.459  | 55.909  | 1.5     |
|             | 19:27:28   | 19:32:28   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 15.949  | 53.182  | 1.5     |
|             | 19:32:58   | 19:37:58   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 18.823  | 54.545  | 1.4     |
|             | 19:38:27   | 19:43:27   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 17.622  | 57.273  | 1.4     |
|             | 19:43:55   | 19:48:55   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 14.118  | 54.545  | 1.3     |
|             | 19:53:24   | 19:58:24   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 13.671  | 53.182  | 1.3     |
|             | 19:58:51   | 20:03:51   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 18.228  | 53.182  | 1.3     |
|             | 20:04:21   | 20:09:21   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 15.460  | 51.818  | 1.2     |
|             | 20:11:32   | 20:16:32   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 21.022  | 58.636  | 1.2     |
|             | 20:17:00   | 20:22:00   |         |         |         |
| OAJ         | 2020-02-13 | 2020-02-13 | 22.657  | 57.273  | 1.1     |
|             | 20:24:59   | 20:29:59   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| TCA         | 2020-02-13 | 2020-02-16 | 21.137  | 57.548  | 2.5     |
|             | 04:36:17   | 02:37:05   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 17.772  | 57.548  | 2.3     |
|             | 04:43:25   | 22:43:29   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-17 | 23.450  | 60.784  | 1.0     |
|             | 05:02:14   | 19:03:32   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 13.258  | 53.837  | 2.0     |
|             | 19:11:15   | 05:31:22   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 12.289  | 50.125  | 1.4     |
|             | 19:18:02   | 23:09:24   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 17.483  | 50.125  | 1.3     |
|             | 19:24:46   | 23:16:14   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 20.656  | 51.981  | 1.2     |
|             | 20:16:22   | 00:52:22   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-17 | 23.665  | 53.837  | 1.0     |
|             | 20:23:06   | 19:10:13   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-17 | 25.656  | 59.404  | 1.2     |
|             | 20:29:50   | 18:31:05   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-15 | 11.859  | 48.270  | 1.0     |
|             | 20:48:51   | 20:25:06   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 25.966  | 57.548  | 1.0     |
|             | 20:55:31   | 04:01:13   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-16 | 14.408  | 57.548  | 0.9     |
|             | 21:14:43   | 04:20:41   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-17 | 16.335  | 53.837  | 2.8     |
|             | 21:48:01   | 19:29:12   |         |         |         |
| TCA         | 2020-02-13 | 2020-02-17 | 20.236  | 55.692  | 2.6     |
|             | 21:54:46   | 19:33:43   |         |         |         |
| TCA         | 2020-02-14 | 2020-02-16 | 19.412  | 53.837  | 2.1     |
|             | 00:50:26   | 22:57:03   |         |         |         |
| TCA         | 2020-02-14 | 2020-02-17 | 18.597  | 59.404  | 1.2     |
|             | 03:52:33   | 18:24:22   |         |         |         |
| TCA         | 2020-02-14 | 2020-02-15 | 17.021  | 55.692  | 3.0     |
|             | 05:11:13   | 22:48:18   |         |         |         |
| TCA         | 2020-02-14 | 2020-02-15 | 14.586  | 48.270  | 1.0     |
|             | 21:36:19   | 19:33:46   |         |         |         |
| TCA         | 2020-02-14 | 2020-02-16 | 14.754  | 51.981  | 2.3     |
|             | 23:13:35   | 22:50:18   |         |         |         |
| TCA         | 2020-02-15 | 2020-02-16 | 24.764  | 55.692  | 1.0     |
|             | 00:12:07   | 05:26:49   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| TCH         | 2020-02-15 | 2020-02-15 | 28.310  | 14.586  | <0.1    |
|             | 01:13:28   | 01:24:04   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| TRE         | 2020-02-13 | 2020-02-13 | 41.019  | 34.827  | 0.1     |
|             | 16:06:52   | 16:13:10   |         |         |         |
| TRE         | 2020-02-13 | 2020-02-14 | 238.671 | -34.718 | 0.1     |
|             | 20:58:04   | 22:00:09   |         |         |         |
| TRE         | 2020-02-13 | 2020-02-14 | 181.050 | -84.859 | 0.1     |
|             | 21:13:01   | 22:19:18   |         |         |         |
| TRE         | 2020-02-13 | 2020-02-14 | 238.950 | -38.809 | 0.1     |
|             | 21:26:13   | 22:32:34   |         |         |         |
| TRE         | 2020-02-13 | 2020-02-14 | 182.100 | -38.809 | 0.1     |
|             | 21:38:28   | 22:44:55   |         |         |         |
| TRE         | 2020-02-13 | 2020-02-14 | 187.555 | -38.809 | 0.1     |
|             | 21:51:41   | 22:58:07   |         |         |         |
| TRE         | 2020-02-13 | 2020-02-14 | 235.866 | -26.536 | 0.1     |
|             | 22:04:03   | 23:10:23   |         |         |         |
| TRE         | 2020-02-14 | 2020-02-14 | 34.827  | 30.736  | 0.5     |
|             | 15:56:42   | 16:03:02   |         |         |         |
| TRE         | 2020-02-14 | 2020-02-14 | 36.154  | 34.827  | 0.3     |
|             | 16:09:33   | 16:15:59   |         |         |         |
| TRE         | 2020-02-14 | 2020-02-14 | 38.100  | 26.645  | 0.3     |
|             | 16:28:17   | 16:34:37   |         |         |         |
| TRE         | 2020-02-14 | 2020-02-14 | 37.222  | 22.555  | 0.2     |
|             | 16:47:40   | 16:54:06   |         |         |         |
+-------------+------------+------------+---------+---------+---------+

TStart and TEnd refers respectively to the time of the first and last
exposure for a given tile. Observations are not necessarily continuous
  in this interval.
The Probability refers to the 2D spatial probability of the GW skymap
enclosed in a given tile.

These observations cover about 35.7% of the cumulative probability of
the LALInference skymap created on 2020-02-16 05:10:14 (UTC).

The coverage map is available at:
https://grandma-owncloud.lal.in2p3.fr/index.php/s/XgtMhPRxcyL09gR/
download?path=%2F&files=GRANDMA_S200213t_1581968146.svg

No significant transient candidates were found during our low latency
analysis [2,3]. Most of the candidates mentioned in GCN#27051,
GCN#27065, GCN#27095 were contained in our observations. ZTF20aapvtip
and ZTF20aamvoxx were observed by TAROT-Reunion but at a lower sensivity
and hours after ZTF.

GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger
Addicts) is a network of robotic telescopes connected all over the
world with both photometry and spectrometry capabilities for Time-
domain Astronomy [2](https://grandma.lal.in2p3.fr/).

Details on the different telescopes are available on the GRANDMA web
pages.

[1] M. W Coughlin et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz2485
[2] S. Antier et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz3142
[3] K. Noysena et al., ApJ 2019, arXiv:1910.02770

GCN Circular 27118

Subject
LIGO/Virgo S200213t: APO Upper Limits for ZTF20aanakes/AT2020cly
Date
2020-02-18T05:56:04Z (5 years ago)
From
Eric C Bellm at UW <ecbellm@uw.edu>
Eric C. Bellm (UW) and Melissa Graham (UW) report on behalf of the GROWTH
collaboration:

On 2020-02-15 02:23 we imaged the location of ZTF20aanakes/AT2020cly
(Coughlin et al, GCN #27095), a transient located inside the error region
of S200213t (LVC,GCN #27042), using the Astrophysical Research Consortium
Telescope Imaging Camera (ARCTIC) on the Apache Point Observatory 3.5m.

We obtained 120-second exposures in g, r, and i bands.  We do not detect
the transient in any band; we estimate two-sigma detection limits of m_g ~
23.5 mag, m_r ~ 23.0 mag, and m_i ~ 21.5 mag.

We thank the APO staff for their support of this Target of Opportunity
observation.

GCN Circular 27119

Subject
LIGO/Virgo S200213t: No EM counterparts found from continued GECKO observation of host galaxy candidates
Date
2020-02-18T08:36:58Z (5 years ago)
From
Gregory SungHak Paek at SNU <shpaek@astro.snu.ac.kr>
Gregory S.H. Paek (SNU), Myungshin Im (SNU), Hyun-Il Sung (KASI), Gu Lim
(SNU), Joonho Kim (SNU), Sungyong Hwang (SNU), Bomi Park (SNU), Sophia Kim
(SNU), Changsu Choi (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Hyung
Mok Lee (KASI), on behalf of GECKO team

 We continued follow-up observation for host galaxy candidates (Paek et al,
GCN #27067) with the 1.0-m telescope at the Lemonsan Optical Astronomical
Observatory(LOAO), the 1.0-m telescope at the Deokheung Optical Astronomy
Observatory(DOAO), and the 0.61-m telescope ate the Sobaeksan Optical
Astronomy Observatory(SOAO) in the initial and updated localization area of
S200213t (Singer et al, GCN #27042) and overlapped neutrino detection area
(Hussain et al, GCN #27043).

 Each image was taken in R-band with 30 minutes exposure time. No obvious
transient has been identified. The list of the inspected targets is given
below, and upper limit(UL) is for 3-sigma detection.

OBSERVATORY          NAME          DISTANCE[Mpc]         DATE-OBS    DEL_JD
FILTER  UL[AB]   NOTE
----------- ---------------------- ------------- ------------------- ------
------ ------- --------
       LOAO               PGC11312           169 2020-02-14T02:37:28  0.93
      R  21.676 neutrino
       LOAO               UGC02483            91 2020-02-14T04:04:08  1.00
      R  21.511 neutrino
       LOAO 2MASS+03014097+3153413            97 2020-02-14T04:43:56  1.02
      R  21.163 neutrino
       LOAO 2MASS+03012583+3135093           254 2020-02-14T03:15:37  0.96
      R  21.626 neutrino
       LOAO 2MASS+00585413+5236357           138 2020-02-15T03:30:47  1.97
      R  20.945     -
       LOAO 2MASS+01154286+5559475           174 2020-02-15T04:15:28  2.0
     R  21.327     -
       LOAO                PGC7302           100 2020-02-15T04:50:59  2.02
      R  20.751     -
       LOAO 2MASS+01192705+5831151           154 2020-02-15T02:37:38  1.93
      R  20.967     -
       LOAO 2MASS+01183038+5156442           127 2020-02-16T03:50:58  2.99
      R   21.21     -
       LOAO              PGC137452           179 2020-02-16T03:15:08  2.96
      R   21.15     -
       LOAO                PGC7302           100 2020-02-16T02:36:58  2.93
      R   21.06     -
       LOAO              PGC137873           174 2020-02-16T04:35:36  3.02
      R  20.952     -
       LOAO                NGC0020            77 2020-02-18T02:35:55  4.9
     R  20.839     -
       LOAO 2MASS+00583689+5137088           121 2020-02-18T03:15:05  4.96
      R  21.517     -
---------------------------------------------------------------------------------------------------
       DOAO               PGC11312           169 2020-02-14T12:05:30  1.32
      R  21.016 neutrino
       DOAO 2MASS+03012583+3135093           254 2020-02-14T12:36:39  1.35
      R   19.96 neutrino
       DOAO               UGC02483            91 2020-02-14T13:01:41  1.36
      R  18.646 neutrino
---------------------------------------------------------------------------------------------------
       SOAO               PGC11312           169 2020-02-14T10:27:54  1.26
      R  21.432 neutrino
       SOAO 2MASS+03012583+3135093           254 2020-02-14T10:59:41  1.28
      R  21.332 neutrino
       SOAO               UGC02483            91 2020-02-14T11:33:53  1.30
      R  21.062 neutrino
       SOAO 2MASS+03014097+3153413            97 2020-02-14T12:07:19  1.33
      R   20.88 neutrino

We thank the LOAO opertator for performing the observation.

Gravitational-wave EM Counterpart Korean Observatory (GECKO) is a network
of 10+ 0.5m to 1m class telescopes over the world.

GCN Circular 27140

Subject
LIGO/Virgo S200213t: Keck/LRIS spectroscopy of counterpart candidates from the Zwicky Transient Facility
Date
2020-02-19T17:18:10Z (5 years ago)
From
Kishalay De at Caltech, GROWTH <kde@astro.caltech.edu>
Kishalay De (Caltech) reports on behalf of the ZTF and GROWTH collaborations

We report optical spectroscopy of four counterpart candidates
announced by the Zwicky Transient Facility (GCN #27051, #27065) in the
localization region of LIGO/Virgo S200213t (LVC, GCN #27042, #27096),
using the Low Resolution Imaging Spectrometer (Oke et al. 1995) on the
Keck-I 10 m telescope. Observations were performed on UT 2020-02-18.

ZTF20aanaltd / AT2020clt shows features consistent with a SN Ia at z = 0.20.
ZTF20aanamcs / AT2020crc shows broad P-Cygni Balmer emission lines at
z = 0.093, consistent with a SN II.
ZTF20aamvpvx / AT2020clx shows broad Balmer emission features at z =
0.074, consistent with a SN II
ZTF20aamvmzj / AT2020cja  shows a blue featureless continuum.

GCN Circular 27153

Subject
LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
Date
2020-02-20T13:50:37Z (5 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (U. of Birmingham),  K. L. Page (U.Leicester), A. A. Breeveld (MSSL-UCL),
P. Brown (TAMU), M. De Pasquale (Istanbul U.), C. Gronwall (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), M. J. Page (UCL-MSSL),  M. H. Siegel (PSU), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), S. D. Barthelmy (NASA/GSFC), A. P. Beardmore (U. Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA),
V. D���Elia (ASDC), P. A. Evans (U. Leicester),P. Giommi (ASI), D. Hartmann (Clemson U.),
J. A. Kennea (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC),
D. B. Malesani (DTU Space), A. Melandri (INAF-OAB), J. A. Nousek (PSU), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), D. M. Palmer (LANL), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC),  T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), G. Tagliaferri (INAF-OAB),
A. Tohuvavohu (U Toronto), and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:

We report Swift/UVOT and XRT follow-up observations of ZTF20aamvmzj (AT2020cja; Kasliwal et al.,
GCN Circ. 27051) found by Zwicky Transient Facility during the search for the EM counterpart
of the LVC event S200213t (LIGO/VIRGO Collaboration GCN Circ. 27042). This object was also
observed by Lulin (Li et al., GCN Circ. 27082) and spectroscopically by DBSP
(Ho et al., GCN Circ. 27074). 

Swift/UVOT and XRT observations began 6.7 days after the LIGO/VIRGO trigger (LIGO/VIRGO 
Collaboration GCN Circ. 27042). We detect ZTF20aamvmzj in the u and UV filters only. In the
following we give preliminary magnitudes using the UVOT photometric system (Breeveld et al. 
2011, AIP Conf. Proc. 1358, 373):

Filter   T_start(s)   T_stop(s) Exp(s)     Mag

v      577293     588978    228      >19.2
b      576882	  588576    236      >19.92
u      576797	  588492    236      19.05 +/- 0.27
w1     576633	  588408    472      19.46 +/- 0.30
m2     577377	  583756    753      19.82 +/- 0.29
w2     576967	  588902    944      19.64 +/- 0.23

The magnitudes in the table are not corrected for the Galactic extinction due to the
significant reddening of E(B-V) = 0.23 in the direction of the burst (Schlegel et al. 1998).

In XRT, no source was found at the location of ZTF20aamvmzj, down to a 3-sigma upper limit of
3.1e-3 count s^-1 in 3 ks of exposure. Assuming a power-law spectrum with NH=3x10^20 cm^-2, and
photon index (Gamma)=1.7, this equates to a upper limit of F < 1.2x10^-13 erg cm^-2 s^-1 on
the 0.3-10 keV observed flux.

This circular is an official product of the Swift team.

GCN Circular 27154

Subject
LIGO/Virgo S200213t: AT2020clw/ZTF20aanaoyz, AT2020crd/ZTF20aanakge and AT2020cly/ZTF20aanakes 10.4m GTC spectroscopy
Date
2020-02-20T15:31:10Z (5 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
Y.-D. Hu, A. J. Castro-Tirado (IAA-CSIC), A. F. Valeev and V. Sokolov 
(SAO-RAS), E. Fernandez-Garcia (IAA-CSIC), I. Carrasco and A. Castellon 
(UMA), M. D. Caballero-Garcia (ASU-CAS), S. B. Pandey (ARIES), G. 
Lombardi and S. Geier (GRANTECAN, IAC, ULL), on behalf of a larger 
collaboration, report:

Following the detection of AT2020clw/ZTF20aanaoyz, 
AT2020crd/ZTF20aanakge and AT2020cly/ZTF20aanakes (Kasliwal et al. GCNC 
27051, Coughlin et al. GCNC 27095) within the error area of the GW event 
S200213t (LVC, GCNC 27042), we obtained optical spectra covering the 
range 3700-7400 A with the 10.4m GTC telescope equipped with OSIRIS in 
La Palma (Spain). Details follow:

For AT2020clw/ZTF20aanaoyz, a magnitude r'= 21.10 +/- 0.09 at 2020-02-15 
20:11 UT is derived. The GTC spectrum is consistent with a SN Ia (near 
maximum) at z = 0.276 +/- 0.005.

For AT2020crd/ZTF20aanakge, a magnitude r'= 19.85 +/- 0.03 at 2020-02-19 
20:42 UT is derived. The GTC spectrum is consistent with a SN Ia (near 
maximum) at z = 0.1272 +/- 0.0005.

For AT2020cly/ZTF20aanakes, no optical counterpart is detected in the 
r'-band 60s exposure image (2020-02-19 20:36UT) within the reported 
position down to 24.9 mag at three-sigma confidence level, which 
confirmed the non-detection reported by Bellm et al (GCNC 27118).

Therefore we consider that AT2020clw/ZTF20aanaoyz and 
AT2020crd/ZTF20aanakge are unrelated to the S200213t GW alert.

We thank the staff at GTC for their excellent support.

GCN Circular 27224

Subject
LIGO/Virgo S200213t: Upper limits from Konus-Wind observations
Date
2020-02-26T15:00:02Z (5 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:

Konus-Wind (KW) was observing the whole sky at the time of the
LIGO/Virgo event S200213t (2020-02-13 04:10:40.328 UTC, hereafter T0;
LIGO/Virgo Collaboration GCN Circ. 27042).

No triggered KW GRBs happened between ~2 days before and ~6 days
after T0. The closest waiting-mode GRB was observed ~1.5 days before T0.
Using waiting-mode data within the interval T0 +/- 100 s,
we found no significant (> 5 sigma) excess over the background
in both KW detectors on temporal scales from 2.944 s to 100 s.

We estimate an upper limit (90% conf.) on the 20 - 1500 keV fluence
to 8.4x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a
typical KW short GRB spectrum (an exponentially cut off power law with
alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band
function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding
limiting peak flux is 2.4x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s 
scale).

All the quoted values are preliminary.

GCN Circular 27258

Subject
LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
Date
2020-02-28T14:42:34Z (5 years ago)
Edited On
2025-04-09T18:43:30Z (2 months ago)
From
Gu Lim at Seoul National U <lim9gu@gmail.com>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Tyler Barna at University of Minnesota <tylerpbarna@gmail.com>
SUBJECT : LIGO/Virgo S200213t: No significant EM counterparts identified
from continued GECKO observation of host galaxy candidates

Gu Lim (SNU), Myungshin Im (SNU), Gregory S.H. Paek (SNU), Joonho Kim
(SNU), Sungyong Hwang (SNU), Bomi Park (SNU), Sophia Kim (SNU), Changsu
Choi (SNU), Shuhrat A. Ehgamberdiev (UBAI), Otabek Burkhonov (UBAI), Davron
Mirzaqulov (UBAI), Hyung Mok Lee (KASI), on behalf of GECKO team

We performed follow-up observation for host galaxy candidates (Paek et al.
GCN #27067, GCN #27119) continuously using AZT-22 1.5m telescope at
Maidanak Astronomical Observatory in Uzbekistan in the initial and updated
localiztion area of S200213t (Singer et al, GCN #27042) and overlapped
neutrino detection area (Hussain et al, GCN #27043).

No significant EM counterpart candidates were found in the stacked images.
Single images were taken in B and R-band of 180 or 300 seconds. Observation
results are listed below. DEPTH is 5-sigma detection limit for point source
in AB magnitude. Flux calibration is conducted using APASS DR9 catalog.

 NAME                   RA[J2000]       DEC[J2000]
DISTANCE[Mpc]    DATE-OBS [UT]    FILTER  EXPTIME[s] DEPTH[AB]
================================================================================================================================
PGC11312                02:59:27.180 +31:23:09.161    169
 2020-02-14T14:33:57    B       1500        23.35
PGC11312                02:59:27.180 +31:23:09.161    169
 2020-02-20T14:33:12    B        900        23.05
PGC11312                02:59:27.180 +31:23:09.161    169
 2020-02-14T15:01:51    R       1500        22.08
PGC11312                02:59:27.180 +31:23:09.161    169
 2020-02-20T14:50:37    R        900        22.64
UGC02483                03:01:36.753 +31:49:09.293     91
 2020-02-14T16:33:02    B        600        18.42
UGC02483                03:01:36.753 +31:49:09.293     91
 2020-02-20T15:53:40    B        900        22.29
UGC02483                03:01:36.753 +31:49:09.293     91
 2020-02-20T16:11:05    R        900        21.84
2MASS+03014097+3153413  03:01:40.977 +31:53:41.330     97
 2020-02-20T16:34:54    B        900        22.72
2MASS+03014097+3153413  03:01:40.977 +31:53:41.330     97
 2020-02-20T16:52:18    R        900        22.00
2MASS+03012583+3135093  03:01:25.837 +31:35:09.301    254
 2020-02-14T15:39:28    B       1500        23.40
2MASS+03012583+3135093  03:01:25.837 +31:35:09.301    254
 2020-02-20T15:13:47    B        900        23.18
2MASS+03012583+3135093  03:01:25.837 +31:35:09.301    254
 2020-02-14T16:06:57    R       1500        22.88

We thank all staff in Maidanak observatory for performing the observation.
Gravitational-wave EM Counterpart Korean Observatory (GECKO) is a network
of 10+ 0.5m to 1m class telescopes over the world.
���

GCN Circular 27400

Subject
LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
Date
2020-03-17T13:54:01Z (5 years ago)
From
Samantha Oates at MSSL <samantha.oates@alumni.ucl.ac.uk>
S. R. Oates (U. of Birmingham),  N. J. Klingler (PSU), K. L. Page (U.Leicester), A. A. Breeveld (MSSL-UCL),
P. Brown (TAMU), M. De Pasquale (Istanbul U.), C. Gronwall (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), M. J. Page (UCL-MSSL),  M. H. Siegel (PSU), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), S. D. Barthelmy (NASA/GSFC), A. P. Beardmore (U. Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA),
V. D'Elia (ASDC), P. A. Evans (U. Leicester),P. Giommi (ASI), D. Hartmann (Clemson U.),
J. A. Kennea (PSU),  H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), D. B. Malesani (DTU Space),
A. Melandri (INAF-OAB), J. A. Nousek (PSU), P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester),
C. Pagani (U. Leicester),   D. M. Palmer (LANL), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), 
T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U Toronto), 
and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:

We report continued Swift/UVOT and XRT observations of ZTF20aamvmzj (AT2020cja; Kasliwal et al.,
GCN Circ. 27051) found by Zwicky Transient Facility during the search for the EM counterpart
of the LVC event S200213t (LIGO/VIRGO Collaboration GCN Circ. 27042). This object was also
observed by Lulin (Li et al., GCN Circ. 27082) and spectroscopically by DBSP (Ho et al., GCN Circ. 27074). 
The Swift/UVOT detection was reported in Oates et al., (GCN Circ. 27153).

Swift/UVOT and XRT has monitored this source from 6.7 days until 29 days after the LIGO/VIRGO trigger
(LIGO/VIRGO Collaboration GCN Circ. 27042). During this time the source was observed to decay and we
no longer detect the source in any filter. In the following we give preliminary 3 sigma upper limits,
combining images from the last two observations, using the UVOT photometric system (Breeveld et al. 
2011, AIP Conf. Proc. 1358, 373):

Filter   T_start(s)   T_stop(s) Exp(s)     3sigUL

v        1714547      2505112    428        > 19.8
b     	 1713986      2504817	 428        > 20.7
u     	 1713871      2504756	 428        > 20.2
w1     1713647      2504694	 857        > 20.2
m2     1714661      2505297	 1238       > 20.5
w2     1714102      2505050    1717       > 20.8

The magnitudes in the table are not corrected for the Galactic extinction due to the
significant reddening of E(B-V) = 0.23 in the direction of the burst (Schlegel et al. 1998).

Combining all 14.4 ks of XRT data collected to date, no source is detected down to a count rate
of 6.7x10^-4 count s^-1. This corresponds to a 3-sigma upper limit of 2.9x10^-14 erg cm^-2 s^-1,
assuming a standard power-law spectrum with NH=3x10^20 cm^-2, and photon index (Gamma)=1.7.

This circular is an official product of the Swift team.

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