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GRB 200115A

GCN Circular 26771

Subject
GRB 200115A: Swift detection of a burst
Date
2020-01-15T12:10:54Z (5 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
S. B. Cenko (GSFC), E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA),
V. D'Elia (SSDC), J.D. Gropp (PSU), N. J. Klingler (PSU) and
K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 11:50:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200115A (trigger=949361).  Swift did not slew to the burst. 
The BAT on-board calculated location is RA, Dec 56.454, +5.613 which is 
   RA(J2000) = 03h 45m 49s
   Dec(J2000) = +05d 36' 46"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 300 sec.  The peak count rate
was ~2600 counts/sec (15-350 keV), at ~101 sec after the trigger. 

Due to observations at a higher merit related to the follow-up 
of the GW event S200115j, Swift will not slew to the BAT position. 
There will thus be no XRT or UVOT data for this trigger. 

Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)

GCN Circular 26772

Subject
GRB 200115A: Nanshan-0.6m optical upper limit
Date
2020-01-15T12:56:33Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu, D. Xu, X. Liu, B.Y. Yu, Y. Ma (NAOC), X. Gao (Urumqi No.1 
Senior High School) report:

We observed the field of GRB 200115A (Cenko et al., GCN 26771) using the 
0.6m NEXT telescope located at Nanshan, Xinjiang, China. Observations 
started at 12:11:17 UT on 2020-01-15 (i.e., 20.9 min after the BAT 
trigger), and a series of 300 s R-band frames have been obtained. 
Observations are ongoing.

No optical transient is detected in the Swift BAT's error circle from 
initial frames, down to a limiting magnitude of m(R) ~ 20.0, calibrated 
with the nearby SDSS field.

GCN Circular 26776

Subject
GRB 200115A: MITSuME Okayama optical upper limits
Date
2020-01-15T15:01:10Z (5 years ago)
From
Masafumi Niwano at Tokyo Institute of Tech <niwano@hp.phys.titech.ac.jp>
M. Niwano, K. L. Murata, M. Oeda, K. Shiraishi, K. Iida, R. Adachi, F. 
Ogawa, S. Toma, R. Hosokawa, N. Nakamura, Y. Yatsu, and N. 
Kawai(TokyoTech) report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 200115A (S. B. Cenko et 
al.,GCN Circular #26771) with the optical three color (g', Rc, and Ic) 
CCD cameras attached to the MITSuME 50 cm telescope of Okayama 
Astrophysical Observatory, Okayama, Japan.
The observation started on 11:52:38.68 UT. We did not find any new point 
sources within the Swift/BAT circle (S. B. Cenko et al., GCN Circular 
#26771) in all three bands.
We obtained the 5-sigma limits as follows.

T0+[sec]���� MID-UT������ T-EXP[sec]������ 5-sigma limits
------------------------------------------------------------------------------------------------
135���� 12:23:04.98���� 3060���� g'>18.3, Rc>17.6, Ic>17.2
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used UCAC4 catalog for flux calibration.
The magnitudes are expressed in the AB system.
The images were processed in real-time through the MITSuME GPU reduction 
pipeline (Niwano et al. ,in prep; https://github.com/MNiwano/Eclair)

GCN Circular 26780

Subject
GRB 200115A: Swift-BAT refined analysis
Date
2020-01-16T00:41:51Z (5 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
K. Page (UL), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 200115A (trigger #949361)
(Page, et al., GCN Circ. 26771).  The BAT ground-calculated position is
RA, Dec = 56.453, 5.607 deg, which is
   RA(J2000)  =  03h 45m 48.7s
   Dec(J2000) = +05d 36' 26.0"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.

The mask-weighted light curve starts before T-50 sec, picking up at T-30 sec,
continued increasing until the peak at T+100 sec, a couple weak following peaks,
and having weak and flat emission out past the end of data at T+240 sec.
T90 (15-350 keV) is 158.4 +- 32.6 sec (estimated error including systematics).

The time-averaged spectrum from T-40.29 to T+233.12 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.29 +- 0.24,   
and Epeak of 75.0 +- 17.5 keV (chi squared 40.88 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.0 +- 0.0 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T+99.75 sec in the 15-150 keV band is
3.6 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index  
of 1.77 +- 0.06 (chi squared 53.76 for 57 d.o.f.).  All the quoted errors 
are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/949361/BA/

GCN Circular 26790

Subject
GRB 200115A: Mondy optical afterglow candidate
Date
2020-01-16T18:22:00Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), A. Volnova (IKI),  E. Klunko (ISTP), K. Kamyshnikov 
(HSE), N. Pankov (HSE),  E. Mazaeva (IKI), S. Belkin (IKI)  report   on 
behalf of GRB IKI FuN:

We observed the field of  GRB 200115A (Cenko et al.  GCN 26771) with 
AZT-33IK telescope of Sayan observatory (Mondy) starting on Jan. 15 (UT) 
  11:55:00, i.e. 4.6 minutes after GRB trigger.  Within  BAT 
ground-calculated position (Laha et al. GCN 26780) we   detected the 
only one unidentified object at the coordinates (J2000) 03:45:46.58 
+05:36:36 with uncertainty of 0.5 arcsec in both coordinates. The object 
is absent in SDSS DR12. At this time we cannot confirm variability of 
the object.   We suggest the object is the optical afterglow  of GRB 
200115A. Preliminary photometry of the afterglow candidate is following.

Date       UT start   t-T0       Filter Exp.    OT    Err.  UL(3sigma)
                       (mid, days)        (s)

2020-01-15 11:55:00   0.02455    R      30*120  20.9  0.2   22.1

The photometry is based on the nearby SDSS DR12 stars
SDSS                 R_Lupton
J034551.63+053704.5  17.138  0.016
J034547.51+053555.6  18.214  0.029
J034543.70+053549.4  17.851  0.022

GCN Circular 26792

Subject
GRB 200115A: DDOTI/OAN optical observations report
Date
2020-01-16T20:59:20Z (5 years ago)
From
Emma Margarita Pereyra Talamantes at IA-UNAM Ensenada <mpereyra@astro.unam.mx>
Rosa L. Becerra (UNAM), Margarita Pereyra (UNAM), Nat Butler (ASU), Alan M.
Watson (UNAM),  Eleonora Troja (GSFC/UMD),  Diego Gonzalez (UNAM),
Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), and Tanner Wolfram
(ASU), Simone Dichiara (GSFC/UMD) report:

We observed the field of GRB 200115A detected by BAT/Swift (Cenko, GCN
Circ. 26771), with the DDOTI/OAN wide-field imager at the Observatorio
Astron��mico Nacional on Sierra San Pedro M��rtir (
http://ddoti.astroscu.unam.mx) from 2020-01-16 02:01 to 2020-01-16 02:19
UTC (14.2 to 14.48 hours after the event).

We observed a region of 6.8 degrees in RA by 10.2 degrees in declination
centered on the peak of the Swift-BAT on-board calculated location
03:45:48.7 +05:36:26.0 J2000. This region contains about 70 square degrees.
We obtained about 16 minutes total exposure across the region.

We calibrated our images against the APASS catalog. Our 3-sigma limiting
magnitude is w = 19.80 for the enhanced Swift-BAT error region (Laha et
al., GCN Circ. 26780). Comparing to the USNO-B1 and SDSS DR9 catalogs we do
not detect any uncataloged source  to our 3-sigma limit.

We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.


-- 
*Dr. Margarita Pereyra *

*FFTF, Schlumberger Foundation Alumnae*
----------------------------------------------------------------------------------------------------------------

*Catedr��tico Conacyt*

*Instituto de Astronom��a de la UNAM,*

*Km. 107 Carretera Tijua**na-Ensenada, *

*Ensenada Baja California, M��xico. C.P. 22860*

Oficina: 405

Skype: margarita-pereyra

GCN Circular 26801

Subject
GRB 200115A: AROMA-N Optical Observation
Date
2020-01-17T12:46:20Z (5 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
M. Nakamura, T. Sakamoto (AGU)

We observed the field of GRB 200115A detected by Swift
(Cenko et al., GCN Circ. 26771) with the 14-inch AGU Robotic
Optical Monitor for Astrophysical object - Narrow (AROMA-N)
located at the Sagamihara campus of Aoyama Gakuin University.

60 images of 60 sec exposures were taken in the R filter
starting from January 15 12:14:42 (UT) about 24 minutes
after the trigger and stopped on January 15 13:27:55 (UT).
We do not detect the optical afterglow both in the individual
images and the stacked image.  The estimated five sigma
upper limit of the combined image (total exposure of 3600 sec)
is ~18.1 mag using the USNO-B1 catalog.

GCN Circular 26809

Subject
GRB 200115A: CALET Gamma-Ray Burst Monitor detection
Date
2020-01-18T02:18:13Z (5 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
T. Tamura (Kanagawa U),
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 (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 very long GRB 200115A detected by Swift (Cenko et al., GCN Circ. 26771,
Laha et al., GCN Circ.26780; https://gcn.gsfc.nasa.gov/other/200115A.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 11:52:05.424 UTC
on 15 January 2020. The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script, the GCN
notice was not distributed automatically for this event.

The burst light curve shows a multi-peaked structure which
starts at T-206 sec, peaks at T-3 sec and ends at T+221 sec.
The T90 and T50 durations measured by the SGM data are 347 +- 46 sec
and 104 +- 29 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1263124124/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.

GCN Circular 26818

Subject
GRB 200115A: Mondy optical observations and correction to GCN 26790
Date
2020-01-19T17:33:26Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), A. Pozanenko (IKI),  E. Klunko (ISTP), K. Kamyshnikov 
(HSE), N. Pankov (HSE),  E. Mazaeva (IKI), S. Belkin (IKI)  report   on 
behalf of GRB IKI FuN:

We observed the field of  GRB 200115A (Cenko et al.,  GCN 26771) with 
AZT-33IK telescope of Sayan observatory (Mondy) starting on Jan. 16 (UT) 
  12:30:28. Within  BAT ground-calculated position (Laha et al. GCN 
26780) we  do not detect any  unidentified objects in comparison with 
SDSS-DR2. We also not detected the afterglow candidate reported after 
our first epoch observation (Pozanenko et al., GCN 26790).

We report the correction of R-magnitude of the afterglow candidate.
The result presented below overrides previously reported (GCN 26790) 
R-magnitude. We apologize for the typo and possible inconvenience.

Due to shallow upper limit in the second epoch observation  we cannot 
confirm variability of the afterglow candidate.

Date       UT start   t-T0       Filter Exp.    OT    Err.  UL(3sigma)
                       (mid, days)        (s)

2020-01-15 11:55:00   0.02455    R      30*120  21.9  0.2   22.1
2020-01-16 12:30:28   1.05039    R      32*120  n/d   n/d   21.6

The photometry is based on the nearby SDSS DR12 stars
SDSS                 R_Lupton
J034551.63+053704.5  17.138  0.016
J034547.51+053555.6  18.214  0.029
J034543.70+053549.4  17.851  0.022

GCN Circular 26872

Subject
GRB 200115A: Assy optical observations
Date
2020-01-24T17:57:09Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), V. Kim (AFIF), A. Pozanenko (IKI), M. Krugov (AFIF), 
E. Mazaeva  (IKI), S. Belkin (IKI) report on behalf of larger GRB IKI 
FuN collaboration:

We observed the field of  GRB 200115A (Cenko et al.,  GCN 26771)  with 
AZT-20 1.5 m telescope  of Assy-Turgen observatory  starting on Jan. 18 
(UT) 16:55:27  in  r'-filter.   We do not detect the afterglow candidate 
(GCNs 26790, 26818) up to r'=22.8 (AB) and hence we consider the object 
found in BAT error circle (Cenko et al.,  GCN 26771) as the optical 
afterglow of GRB 200215A.

Photometry of the field is following.

Date       UT start   t-T0       Filter Exp.   OT   UL (3sigma)
                       (mid, days)        (s)

2019-10-18 16:55:27   3.22608     r'    13*180 n/d  22.8

The photometry is based on the nearby SDSS-DR12 stars.

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