GRB 150120B
GCN Circular 17651
Subject
GRB 150120B: GMG observation
Date
2015-03-29T08:21:35Z (11 years ago)
From
Jirong Mao at Yunnan Obs <jirongmao_obs@ynao.ac.cn>
J. Mao, J. Zhang, and J.-M. Bai (YNAO) report:
We observed the field of GRB 150120B (D'Elia et al., GCN 17314) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station
of Yunnan Observatory. Observations began from UT 13:42:43.5 20th, Jan., 2015 (about 6.3 hours after the trigger).
We clearly detected the optical counterpart with brightness of R=22.1+/-0.1 mag.
J. Mao apologizes for this very late GCN circular submission.
GCN Circular 17366
Subject
GRB 150120B: Khureltogot optical observations
Date
2015-01-30T21:25:11Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of
Astronomy and Geophysics MAS), A. Volnova (IKI), I.Molotov (KIAM), A.
Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 150120B (D'Elia et al., GCN 17314) with
ORI-40 telescope of Khureltogot observatory on Jan., 20 starting on
(UT) 10:52:51. We obtained 90 unfiltered images of 60 s exposure.
Within enhanced Swift-XRT error circle (Goad et al., GCN 17320) we
clearly detect optical afterglow (Perley et al. GCN 17315, Guidorzi et
al. GCN 17316) in a combined image. Photometry of the afterglow is
following
Date UT start t-T0 Filter Exp. OT OT_err
(mid, days) (s)
2015-01-20 10:52:51 0.18068 none 90*60 20.75 0.20
The photometry is based on R magnitudes of nearby USNO-B1.0 stars
USNO-B1_id R2
0981-0032639 16.04
0981-0032644 17.10
GCN Circular 17347
Subject
GRB 150120B: Mondy optical observations
Date
2015-01-23T19:00:55Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Volnova (IKI), E. Klunko (ISTP), I. Korobtsev
(ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:
We observed the field of GRB 150120B (D'Elia et al., GCN 17314) with
AZT-33IK telescope of Sayan observatory (Mondy) Jan., 20 starting on
(UT) 11:42:02. We obtained 65 images in R-filter of 120 s exposure. In
two combined images within enhanced Swift-XRT error circle (Goad
et al., GCN 17320) we clearly detect optical afterglow (Perley et al.
GCN 17315, Guidorzi et al. GCN 17316). Photometry of the afterglow is
following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2015-01-20 11:42:02 0.20149 R 30*120 21.25 0.22
2015-01-20 12:42:04 0.24348 R 30*120 21.43 0.25
Photometry is based on nearby USNO B1.0 (R2) stars:
USNO-B1.0_id R
0980-0031064 15.57
0980-0031070 14.16
0980-0031080 16.35
0980-0031095 15.41
GCN Circular 17343
Subject
GRB 150120B: RATIR Optical and NIR Observations
Date
2015-01-21T21:24:35Z (11 years ago)
Edited On
2024-11-07T20:02:08Z (2 years ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús
González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:
We observed the field of GRB 150120B (D'Elia, et al., GCN 17314) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on
Sierra San Pedro Mártir from 2015/01 21.09 to 2015/01 21.29 UTC (18.73 to
23.64 hours after the BAT trigger), obtaining a total of 3.91 hours
exposure in the r, i, and z bands.
For a source coincident with the GROND optical transient (Wiseman et al.,
GCN 17336), in comparison with 2MASS, we obtain the following detections
and upper limit (3-sigma):
r = 23.4 +/- 0.2
i = 22.6 +/- 0.1
z > 20.72
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
GCN Circular 17340
Subject
GRB 150120B: FTN early optical light curve
Date
2015-01-21T14:51:41Z (11 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi, S. Dichiara (U. Ferrara), C.G. Mundell (LJMU),
A. Gomboc (U. Ljubljana) on behalf of a large collaboration report:
The 2-m Faulkes Telescope North observed Swift GRB150120B
(D'Elia et al. GCN 17314; Perley GCN 17315) from 18 to 100 minutes
since the burst trigger time with SDSS r and i filters.
Both light curves are fitted with a power-law with a decay index
alpha=0.8 +- 0.1. A comparison with the observations at later times
(Perley GCN 17335; Wiseman et al. GCN 17336; Pandey GCN 17337;
Xin et al. GCN 17339) suggests that a steepening of the decay
must have occurred between ~2e4 and ~6e4 s.
GCN Circular 17339
Subject
GRB150120B: Xinglong TNT optical observation
Date
2015-01-21T14:07:31Z (11 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L. P. Xin, X. F. Wang, J. Y. Wei, Y. L. Qiu, J. S. Deng,
J. Wang, X. H. Han and C. Wu on behalf of EAFON report:
We began to observe GRB 150120B (D'Elia et al., GCN 17314)
with Xinglong 0.8-m TNT telescope at 2015-01-20, 10:56:50 (UT),
about 3.58 hours after the burst.
In the 15*300sec coadded R-bamd image, the optical counterpart
(D. A. Perley GCN 17315; Guidorzi et al., GCN 17316; Wiseman et al., 17336;
Pandey GCN 17337) was detected with a brightness of
R=21.3+/-0.2 mag at the mid-time of 4.2 hours after the burst,
calibrated by the nearby USNO B1.0 R2 mag.
The message may be cited.
GCN Circular 17338
Subject
GRB 150120B: Swift/UVOT Upper Limits
Date
2015-01-21T13:36:09Z (11 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
GRB 150120B: Swift/UVOT Upper Limits
M. M. Chester (PSU) and V. D'Elia (ASDC) report on behalf
of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150120B
432 s after the BAT trigger (D'Elia et al., GCN Circ. 17314).
No source consistent with the optical afterglow reported by Perley
(GCN Circ. 17315) and Guidorzi et al. (GCN Circ. 17316) is detected
in the initial UVOT exposures. Preliminary 3-sigma upper limits
using the UVOT photometric system (Breeveld et al. 2011, AIP Conf.
Proc. 1358, 373) for the first finding chart (FC) exposure and
subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 432 582 147 >19.9
white 432 1014 295 >20.5
white 7279 7479 197 >20.7
v 6254 19560 1278 >20.1
b 7074 25878 979 >20.9
u 6869 25353 1999 >21.0
w1 639 2670 214 >19.6
w1 6664 24440 2164 >21.0
m2 6459 20294 1996 >21.0
w2 1885 3036 124 >19.5
w2 7484 18646 1082 >20.8
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.20 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 17337
Subject
GRB 150120B, Optical observations
Date
2015-01-21T12:02:24Z (11 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S. B. Pandey (ARIES Nainital India, on behalf of larger Indian GRB
collaboration)
The 1.04m Sampurnanand telescope at ARIES Nainital began observations
of the Swift-detected GRB 150120B (D'Elia et al., GCN 17314) starting at
13:34:44 UT on 2015-01-20. Several frames in R_c pass-band 300sec each
were acquired in poor sky conditions.
In the co-added image (6x300 sec), we detect the optical afterglow candidate
at R_c ~ 21.7+-0.1 mag to the location consistent with that reported by
Perley et al. (GCN 17315), Guidorzi et al. (GCN 17316). The temporal
power-law
flux decay seems to follow an index of 0.7 at the epoch of our observations
as reported by Perley & Cenko (GCN 17335). The photometry was performed in
comparison to nearby USNO- B1 stars.
This massage may be cited.
GCN Circular 17336
Subject
GRB 150120B: GROND Afterglow Detection
Date
2015-01-21T09:14:34Z (11 years ago)
From
Philip Wiseman at MPE/Swift <wiseman@mpe.mpg.de>
P Wiseman, J Graham, P Schady and J Greiner (All MPE Garching) report on
behalf of
the GROND team:
We observed the field of GRB 150120B (Swift trigger 627170; D'Elia et al.,
GCN 17314) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).
Observations started at 01:25 UT on 21.01.2015, ~18hrs after the GRB
trigger. They were performed at an average seeing of 1.1" and at an
average airmass of 1.7.
We find a single point source within the 1.4" Swift-XRT error circle (Goad
et al., GCN 17320), consistent with that
reported by Perley et al. (GCN 17315), Guidorzi et al. (GCN 17316), at
RA (J2000.0) = 02 h 37 m 09.77 s
DEC (J2000.0) = +08d 04' 40.49"
with an uncertainty of 0.3" in each coordinate.
Based on 25 min of total exposures in g'r'i'z'JHK, we estimate preliminary
magnitudes and 3 sigma upper limits (all in AB system) of
g' > 24.2
r' = 23.6 +/- 0.1 mag,
i' = 22.7 +/- 0.2 mag,
z' = 22.4 +/- 0.40 mag,
J = 20.2 +/- 0.3 mag,
H = 19.9 +/- 0.5 mag, and
K = 18.7 +/- 0.4 mag.
Based on these magnitudes, the best-fit SED has a break in the g' band
suggesting a photometric redshift of 3.5 +/-0.5.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.17 mag in the
direction of the burst (Schlegel et al. 1998).
GCN Circular 17335
Subject
GRB 150120B: Additional P60 observations
Date
2015-01-21T03:32:27Z (11 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) and S. B. Cenko (NASA/GSFC) report:
We obtained further observations at the position of the optical
afterglow (Perley, GCN 17315) of GRB 150120B (D'Elia et al., GCN 17314)
with the Palomar 60-inch robotic telescope on the night of 2015-01-21
UT. In a combined stack of five 300-second r-band exposures we no
longer detect any significant emission at the location of the optical
afterglow. We estimate a limiting magnitude of r>22.7 mag (3 sigma) at
a mid-time of 02:32:27 UT, t=0.799 days after the GRB. Relative to our
previous observations, this suggests a decay power-law slope of at least
alpha>0.75.
GCN Circular 17331
Subject
GRB 150120B: MITSuME Okayama upper limits
Date
2015-01-21T01:24:44Z (11 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:
We observed the field of GRB 150120B (D'Elia et al., GCNC 17314)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2015-01-20 11:12:04 UT (~3.8 h after the burst).
We could not detect the previously reported afterglow (Perley, GCNC 17315;
Guidorzi et al., GCNC 17316) in all the three bands.
Three sigma upper limits of the OT are listed below.
We used GSC2.3 catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' Rc Ic
-----------------------------------------------------
0.20162 12:12:15 5760.0 >19.6 >19.6 >19.1
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 17330
Subject
GRB 150120B: Swift-BAT refined analysis
Date
2015-01-20T22:51:16Z (11 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC) N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 150120B (trigger #627170)
(V. D'Elia, et al., GCN Circ. 17314). The BAT ground-calculated position is
RA, Dec = 39.309, 8.064 deg which is
RA(J2000) = 02h 37m 14.1s
Dec(J2000) = +08d 03' 50.3"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
The mask-weighted light curve shows a multi-peaked structure starts at ~ T-20 s
and ends at ~ T+10 s, with the main peak at ~ T+0 s. T90 (15-350 keV)
is 24.30 +- 3.39 sec (estimated error including systematics).
The time-averaged spectrum from T-17.64 to T+9.63 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.20 +- 0.25. The fluence in the 15-150 keV band is 5.4 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.58 sec in the 15-150 keV band
is 1.2 +- 0.2 ph/cm2/sec. 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/627170/BA/
GCN Circular 17325
Subject
GRB 150120B: Swift-XRT refined Analysis
Date
2015-01-20T20:51:04Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.A. Kennea (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), M. de Pasquale (INAF-IASFPA), A.
Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), V. Mangano (PSU), M.C.
Stroh (PSU) and V. D'Elia report on behalf of the Swift-XRT team:
We have analysed 9.0 ks of XRT data for GRB 150120B (D'Elia et al. GCN
Circ. 17314), from 438 s to 19.9 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Goad et al. (GCN Circ. 17320).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.91 (+/-0.05).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.97 (+0.14, -0.15). The
best-fitting absorption column is 3.2 (+0.7, -0.8) x 10^21 cm^-2, in
excess of the Galactic value of 1.2 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.8 x 10^-11 (5.6 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.2 (+0.7, -0.8) x 10^21 cm^-2
Galactic foreground: 1.2 x 10^21 cm^-2
Excess significance: 4.5 sigma
Photon index: 1.97 (+0.14, -0.15)
If the light curve continues to decay with a power-law decay index of
0.91, the count rate at T+24 hours will be 6.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.6 x
10^-13 (3.8 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00627170.
This circular is an official product of the Swift-XRT team.
GCN Circular 17320
Subject
GRB 150120B: Enhanced Swift-XRT position
Date
2015-01-20T15:06:41Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 5081 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 150120B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 39.29070, +8.07795 which is equivalent
to:
RA (J2000): 02h 37m 9.77s
Dec (J2000): +08d 04' 40.6"
with an uncertainty of 1.4 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 17316
Subject
GRB 150120B: FTN optical afterglow confirmation
Date
2015-01-20T08:44:28Z (11 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi, S. Dichiara (U. Ferrara), C.G. Mundell (LJMU),
A. Gomboc (U. Ljubljana) on behalf of a larger collaboration report:
The 2-m Faulkes Telescope North began observing Swift GRB150120B
(D'Elia et al. GCN 17314) on Jan 20 at 07:39:45 UT
(~18 minutes after the burst trigger) with SDSS r and i filters.
We clearly detect the optical candidate reported by Perley (GCN
17315), with a magnitude of r=19.21 +- 0.07 calibrated against
nearby USNOB-1 (R1) stars.
GCN Circular 17315
Subject
GRB 150120B: P60 optical afterglow
Date
2015-01-20T08:11:39Z (11 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
The Palomar 60-inch robotic telescope began automatic follow-up of the
location of GRB 150120B (D'Elia et al., GCN 17314) starting at 07:26:07
UT on 2015-01-20.
In the first three 60-second frames (r, i, and z-bands) we detect a
bright (r~18.7 mag), new source at the following location (J2000):
RA = 02:37:09.770
dec = +08:04:40.37
After these three frames, the telescope received the initial XRT
position notice and it executed a large slew to a new position, and this
optical source was no longer in the field of view. It returned to the
field with the updated XRT position notice in an image starting at
07:47:47; the GRB afterglow shows significant fading (to r~19.7 mag) in
this observation since the first epoch, confirming it as the optical
afterglow.
We also note that the optical position above is near, but significantly
outside (7 arcsec west) of, the updated XRT position given in GCN 17314.
[GCN OPS NOTE(20jan15): Per author's request, the GRB name in the
Subject-line was changed from 140120B to 150120B.]
GCN Circular 17314
Subject
GRB 150120B: Swift detection of a burst
Date
2015-01-20T07:51:54Z (11 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
V. D'Elia (ASDC), L. Izzo (URoma/ICRA), N. P. M. Kuin (UCL-MSSL),
A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), D. M. Palmer (LANL)
and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 07:21:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 150120B (trigger=627170). Swift slewed to this burst
after a short delay due the Earth limb constraint.
The BAT on-board calculated location is
RA, Dec 39.294, +8.079 which is
RA(J2000) = 02h 37m 11s
Dec(J2000) = +08d 04' 43"
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 30 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 07:29:01.2 UT, 425.7 seconds after
the BAT trigger. The position determined from promptly downlinked data
differs significantly from the on-board position, suggesting that the
XRT may have centroided on a cosmic ray; the initial XRT position
notice should be treated with caution. Using promptly downlinked data
we find an uncatalogued X-ray source with an enhanced position: RA, Dec
39.2927, 8.0781 which is equivalent to:
RA(J2000) = 02h 37m 10.25s
Dec(J2000) = +08d 04' 41.2"
with an uncertainty of 2.7 arcseconds (radius, 90% containment). This
location is 5.7 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. We cannot determine whether the source is
fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.16
x 10^21 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 432 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.20.
Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it).
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/too.html.)