GRB 191221B
GCN Circular 26990
Subject
MeerKAT observation of GRB 191221B
Date
2020-02-05T19:25:22Z (6 years ago)
From
Itumeleng Monageng at UCT/SAOO <itu@saoo.ac.za>
Dear GCN circular admin,
This email serves to submit details of the radio observation of GRB191221B with MeerKAT. Please see the detail of the GCN draft below.
I. Monageng (UCT/SAAO), M. Boettcher (NWU), D.A.H Buckley (SAAO), R. Britto (UFS), S. Razzaque (UJ), B. van Soelen (UFS)
We observed GRB 191221B with the MeerKAT radio telescope on 21 January 2020 from 20:26 to 21:26 UTC (~30 days after the trigger) at a position consistent with the X-ray position reported by Beardmore et al. (GCN 26540). We used J0408-6545 as the bandpass and flux calibrator, which was observed for 10 minutes at the start of the observation. The phase calibrator used was J1120-2508, which was observed for 2 minutes before and after the two ~20 minute scans on GRB 191221B (20:41:04.0 - 21:00:55.5 and 21:03:51.5 - 21:23:50.9 UTC). The observation was performed with 60 antennas and is centered at a frequency of 1.28 GHz with a bandwidth of 856 MHz over 4096 channels. The GRB afterglow was not detected, and we report a 3-sigma upper limit of 64 micro Jy at the position of GRB 191221B.
We thank the team at the South African Radio Astronomy Observatory (SARAO) for observing this DDT request.
Best regards,
Itu
--
-------------------------------------------
Dr. Itumeleng M. Monageng
South African Astronomical Observatory/University of Cape Town
Tel: +27(0) 21 460 9359 (SAAO)
Tel: +27(0) 21 650 7347 (UCT)
Cell: 076 885 5437
GCN Circular 26616
Subject
GRB 191221B: CALET Gamma-Ray Burst Monitor detection
Date
2019-12-31T02:44:42Z (6 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
S. Sugita, A. Yoshida, T. Sakamoto, V. Pal'shin (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 long GRB 191221B (Swift detection: Barthelmy et al., GCN Circ. 26534,
Sakamoto et al., GCN Circ. 26562; AGILE/MCAL observations: Longo et al.,
GCN Circ. 26549; AstroSat CZTI detection: Gaikwad et al., GCN Circ. 26567;
Insight-HXMT/HE detection: Xue et al., GCN Circ. 26573;
Konus-Wind observation: Frederiks et al., GCN Circ. 26576;
https://gcn.gsfc.nasa.gov/other/191221B.gcn3) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 20:39:04.868 UTC on 21 December 2019.
The burst signal was seen by all CGBM detectors.
The burst light curve shows a multi-peaked pulse which starts
at T+1.8 sec, peaks at T+11.3 sec and ends at T+23.4 sec.
The T90 and T50 durations measured by the SGM data are
13.0 +- 1.6 sec and 4.4 +- 0.4 sec (40-1000 keV), respectively.
The ground processed light curve will be available at
http://cgbm.calet.jp/cgbm_trigger/ground/1260995788/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.
GCN Circular 26580
Subject
GRB 191221B: ATCA detection of the radio afterglow
Date
2019-12-25T16:43:35Z (6 years ago)
From
Tanmoy Laskar at U of Bath <tanmoylaskar@gmail.com>
T. Laskar (University of Bath), S. Bhandari (CSIRO), K. D.
Alexander (Northwestern), E. Berger (Harvard), R. Chornock (Ohio U.), D.
Coppejans (Northwestern), M. Drout (U. Toronto), H. van Eerten (University
of Bath), Wen-fai Fong (Northwestern), C. Guidorzi (U. Ferrara), G.
Hosseinzadeh (Harvard), R. Margutti (Northwestern), C. G. Mundell
(University of Bath), and P. Schady (University of Bath) report:
"We observed GRB 191221B (Laha et al., GCN 26534) with the Australia
Telescope Compact Array (ATCA) at multiple frequencies and multiple epochs
beginning on 2019 December 22 14:17 UT (0.73 days after the burst). We
detect a varying radio counterpart at 5.5, 9.0, 16.7, and 21.2 GHz at a
position consistent with the X-ray position (Beardmore et al., GCN 26540)
and optical position (Lipunov et al., GCN 26537). We identify this source
as the radio afterglow of GRB 191221B.
Further analysis and observations are on-going.
We thank the CSIRO staff for approving these observations."
GCN Circular 26576
Subject
Konus-Wind observation of GRB 191221B
Date
2019-12-24T15:30:57Z (6 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, S. Golenetskii, R.Aptekar, A.Lysenko,
A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 191221B (Swift detection: Laha et al., GCN 26534;
AGILE/MCAL detection: Longo et al., GCN 26549;
AstroSat CZTI detection: Gaikwad et al., GCN 26567)
triggered Konus-Wind (KW) at T0=74349.647 s UT (20:39:09.647).
The burst light curve shows a bright pulse with a complex, multi-peaked structure.
The total duration of the burst is ~35 s.
The emission is seen up to ~15 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB191221_T74349/
As observed by Konus-Wind, the burst had
a fluence of (1.0 �� 0.1)x10^-4 erg/cm^2 and
a 64-ms peak energy flux, measured from T0+8.064,
of (1.9 �� 0.2)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+21.760 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.81 (-0.06,+0.06),
the high energy photon index beta = -2.47 (-0.24,+0.16),
the peak energy Ep = 377 (-29,+30) keV,
chi2 = 99/97 dof.
The spectrum near the peak count rate (measured from T0+6.912 s
to T0+8.448 s) is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.51 (-0.11,+0.13),
the high energy photon index beta = -2.72 (-0.50,+0.26),
the peak energy Ep = 338 (-36,+38) keV,
chi2 = 64/66 dof.
Assuming the redshift z=1.148 (Vielfaure et al., GCN 26553)
and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,
and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the following rest-frame parameters:
the isotropic energy release E_iso = (3.6 �� 0.4)x10^53 erg,
the peak luminosity L_iso = (1.5 �� 0.16)x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum Ep,z=(810 �� 65) keV.
With these values, GRB 191221B is within 68% prediction bands
for both 'Amati' and 'Yonetoku' relations built for the sample
of 138 long KW GRBs with known redshifts (Tsvetkova et al., ApJ 850 161, 2017),
see http://www.ioffe.ru/LEA/GRBs/GRB191221_T74349/GRB191221B.pdf
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
GCN Circular 26574
Subject
GRB 191221B: Swift/UVOT Detection
Date
2019-12-24T12:08:39Z (6 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and S. L. Laha (GSFC/UMBC/CRESST)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 191221B
92 s after the BAT trigger (Laha et al., GCN Circ. 26534).
A source consistent with the XRT position (Beardmore et al. GCN Circ. 26540)
and ALMA position (Laskar et al., GCN Circ. 26564) was detected in the
initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 10:19:19.24 = 154.83017 (deg.)
Dec (J2000) = -38:09:27.64 = -38.15768 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures
are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 92 241 147 see below
u 304 554 246 12.30 +/- 0.02
b 560 579 20 13.54 +/- 0.04
uvw2 610 630 20 13.20 +/- 0.06
v 635 655 20 13.42 +/- 0.05
uvm2 659 679 20 12.79 +/- 0.06
uvw1 684 704 20 12.82 +/- 0.05
Aperture photometry shows initially a completely saturated detector,
leading
to wh < 13.8 mag. The first exposure in the white filter (tstart=T0+92s)
shows a readout streak but the readout streak traverses also another
relatively bright star which leads to a saturated readout streak
and precludes using that method of determining the magnitude (Page
et al, 2013 MNRAS 436, 1684). Analysis continues.
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 26573
Subject
GRB 191221B: Insight-HXMT/HE detection
Date
2019-12-24T08:16:39Z (6 years ago)
From
Wangchen Xue at IHEP <xuewc@ihep.ac.cn>
W. C. Xue, Y. G. Zheng, C. Cai, 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:
At 2019-12-21T20:39:10.70 (T0), Insight-HXMT/HE detected
GRB 191221B (trigger ID: HEB191221860) in a routine search of the data,
which was also triggered by Swift/BAT (GCN #26534).
The Insight-HXMT/HE light curve mainly consists of multiple
pulses with a duration (T90) of 8.85 s measured from T0-0.62 s.
The 1-ms peak rate, measured from T0+5.37 s, is 8262 cnts/sec.
The total counts from this burst is 38429 counts.
URL_LC: http://www.hxmt.org/images/GRB/HEB191221860_LC.jpg
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 telescope.
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 about it could be found at:
http://www.hxmt.org.
GCN Circular 26567
Subject
GRB 191221B: AstroSat CZTI detection
Date
2019-12-23T10:16:07Z (6 years ago)
From
Ramkrishna Gaikwad at IUCAA/AstroSat <ramkrishna@iucaa.in>
R. Gaikwad, S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed the detection of a GRB 191221B, which was also detected by Swift (Laha S. et al., GCN #26534), Global MASTER-Net (Lipunov V. et al., GCN #26536), Swift/UVOT (Kuin N. et al., GCN #26538), Swift-XRT (Beardmore A. et al., GCN #26540), AGILE/MCAL (Longo F. et al., GCN #26549), VIRT (Gokuldass P. et al., GCN #26551), VLT/X-shooter (Vielfaure J. et al., GCN #26553), MASTER VWFC (Lipunov V. et al., GCN #26555), LCO (Strausbaugh R. et al., GCN #26560), Zadko (Gendre B. et al., GCN #26561), ALMA (Laskar T. et al., GCN #26564) and iTelescope (Romanov F. et al., GCN #26565).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2019-12-21 20:39:12.0 UT. The measured peak count rate associated with the burst is 708 cts/s above the background in the combined data of four quadrants, with a total of 4829 cts. The local mean background count rate was 515 cts/s. Using cumulative rates, we measure a T90 of 11.16 s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. 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 26566
Subject
GRB 191221B: iTelescope T17 detection
Date
2019-12-23T02:27:04Z (6 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
A.K.H. Kong (NTHU, Taiwan) reports
We observed the field of GRB 191221B (Laha et al., GCN 26534) with the
T17 0.43m telescope of iTelescope.Net in Siding Spring, Australia. The
observation was done with a SDSS r filter beginning at 2019-12-22
14:56:51 UT (about 18 hours after the trigger) for 300 sec. The
optical counterpart (Laha et al., GCN 26534) was detected with
r=18.4+/-0.1 (AB) by calibrating with the SkyMapper Southern Sky
Survey.
GCN Circular 26565
Subject
GRB 191221B: iTelescope optical observations
Date
2019-12-23T00:21:24Z (6 years ago)
From
Filipp Dmitrievich Romanov at Amateur astronomer <filipp.romanov.27.04.1997@gmail.com>
I observed the optical afterglow of GRB 191221B (Laha et al., GCN Circ.
26534) with remote telescope T32 (0.43-m f/6.8 reflector + FLI Proline
16803 CCD) of iTelescope.Net in Siding Spring Observatory (Australia) on
2019-12-22 since 13:28:52 UT (~16.8 hours after the trigger). Two images
were obtained in each band with Astrodon luminance filter and
Johnson/Cousins V filter for 180 and 120 seconds (Binx2). I detected the
optical afterglow in three images in the enhanced Swift-XRT position
(Beardmore et al., GCN Circ. 26540); it not present in images from DSS
Plate Finder.
The following magnitudes (mag. error ~ 0.2) were measured from comparison
to nearby stars from APASS DR9 catalogue (Henden et al., 2016):
Time of start Exp.time Mag. Comp.star band Filter
----------------------------------------------------------
13:28:52 UT 180 s 18.1 r' Luminance
13:32:58 UT 180 s 18.3 V V
13:36:51 UT 120 s 18.3 r' Luminance
13:39:46 UT 120 s <17.9 V V
----------------------------------------------------------
Magnitudes were not corrected for Galactic extinction.
GCN Circular 26564
Subject
GRB 191221B: ALMA detection
Date
2019-12-22T22:36:28Z (6 years ago)
From
Tanmoy Laskar at U of Bath <tanmoylaskar@gmail.com>
T. Laskar (University of Bath), W. Fong (Northwestern), K. D. Alexander
(Northwestern), E. Berger (Harvard), S. Bhandari (CSIRO), G. Hosseinzadeh
(Harvard), R. Margutti (Northwestern), C. G. Mundell (University of Bath),
and P. Schady (University of Bath) report on behalf of a larger
collaboration:
"We observed GRB 191221B (Laha et al. GCN 26534) with the Atacama Large
Millimeter/Submillimeter Array (ALMA) beginning on 2019 December 22 at
07:43:55 UT (11.1 hr after the burst) at 97.5 GHz under good weather
conditions. Preliminary analysis reveals a bright (S/N > 300) mm source at
position:
10:19:19.225 (+/- 0.005), -38:09:27.45 (+/- 0.01)
consistent with the X-ray position (Beardmore et al. GCN 26540) and optical
position (Lipunov et al., GCN 26537). Follow-up observations are planned.
We thank the JAO staff, AoD, P2G, and the entire ALMA team for their help
with these observations."
GCN Circular 26562
Subject
GRB 191221B: Swift-BAT refined analysis
Date
2019-12-22T21:07:26Z (6 years ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 191221B (trigger #945521)
(Laha et al., GCN Circ. 26534). The BAT ground-calculated position is
RA, Dec = 154.831, -38.152 deg which is
RA(J2000) = 10h 19m 19.3s
Dec(J2000) = -38d 09' 07.1"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 12%.
The mask weighted light curve shows complex structures with a duration of ~30 s.
The overall structure starts at ~T-10 s and lasts till ~T+20s.
There is some hint of weak emission extending up to ~ T+60 s.
T90 (15-350 keV) is 48.00 +- 16.00 sec (estimated error including systematics).
The time-averaged spectrum from T-15.28 to T+96.72 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.24 +- 0.05. The fluence in the 15-150 keV band is 1.9 +- 0.1 x 10^-05 erg/cm2.
the fluence of this burst is among the brightest ~3% of all BAT-detected GRBs
(based on fluences from the BAT GRB catalog https://swift.gsfc.nasa.gov/results/batgrbcat/).
The 1-sec peak photon flux measured from T+8.22 sec in the 15-150 keV band
is 4.8 +- 0.7 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/945521/BA/
GCN Circular 26561
Subject
GRB 191221B: Zadko observatory - Gingin optical observations
Date
2019-12-22T19:43:01Z (6 years ago)
From
Bruce Gendre at UVI <bruce.gendre@gmail.com>
B. Gendre (OzGrav-UWA), H. Crisp (OzGrav-UWA), J. Moore (OzGrav-UWA),
D. Coward (OzGrav-UWA), A. Klotz (IRAP-CNRS-OMP), P. Thierry (Aragne
Observatory), A. Burrell (OzGrav-UWA), J. Zadko (Claire Energy),
M. Boer, (UNS-CNRS-OCA)
report:
We imaged the field of GRB 191221B detected by Swift (trigger 945521,
Laha et al. GCN 26534) with the Zadko robotic telescope (D=100cm)
located at the Zadko observatory - Gingin, Australia.
The observations started 19 hours after the GRB trigger. The elevation
of the field was at 32 degrees above horizon and weather conditions
were good. We performed 6 long exposures of 180s in Clear filter.
We detected the candidate couterpart mentioned by Lipunov et al. (GCNC
26537) in each of the images.
OT was R~17.6+/-0.2 at that time. Further analysis and observations are
ongoing.
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
This message may be cited.
GCN Circular 26560
Subject
GRB 191221B: LCO Optical Detection
Date
2019-12-22T18:20:35Z (6 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 191221B (Laha et al., GCN 26534) with the LCO 1-m Sinistro instrument at the Sutherland South African Astronomical Observatory site on December 22, from 00:30 to 01:11 UT (corresponding to 3.5 to 4.2 hours after the GRB trigger time) with the Bessel R and I filters.
We performed a series of 10x90s exposures in each band. We detect a bright source in the Swift-BAT refined error region (Laha et al., GCN 26536) that is not present in either USNO-B1.0 or 2MASS surveys with the following magnitudes:
R = 16.50 +/- 0.01
I = 15.86 +/- 0.01
This flux measurement is calibrated against several USNO-B1.0 objects near the GRB location and is not corrected for Galactic Extinction.
GCN Circular 26559
Subject
GRB 191221B: Swift-XRT refined Analysis
Date
2019-12-22T17:57:08Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU), A.
Tohuvavohu (U. Toronto), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), M.G. Bernardini (INAF-OAB), E.
Ambrosi (INAF-IASFPA) and S Laha report on behalf of the Swift-XRT
team:
We have analysed 7.8 ks of XRT data for GRB 191221B (S Laha et al. GCN
Circ. 26534), from 74 s to 58.6 ks after the BAT trigger. The data
comprise 1.3 ks in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 26540).
The late-time light curve (from T0+4.9 ks) can be modelled with a
power-law decay with a decay index of alpha=1.03 (+0.09, -0.08).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.097 (+/-0.014). The
best-fitting absorption column is consistent with the Galactic value
of 8.6 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.86 (+0.07, -0.06) and a best-fitting absorption
column consistent with the Galactic value. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 3.6 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Galactic foreground: 8.6 x 10^20 cm^-2
Intrinsic column: 8.6 (+5.8, -0.0) x 10^20 cm^-2 at z=1.148
Photon index: 1.86 (+0.07, -0.06)
If the light curve continues to decay with a power-law decay index of
1.03, the count rate at T+24 hours will be 0.087 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.1 x
10^-12 (3.6 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00945521.
This circular is an official product of the Swift-XRT team.
GCN Circular 26555
Subject
GRB 191221B: MASTER VWFC OT yearly detection
Date
2019-12-22T14:31:51Z (6 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(Lomonosov Moscow State University, SAI, Physics Department),
D. Buckley(South African Astronomical Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
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),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State
University)
We found first image with error box at 2019-12-21 20:40:15 (62 sec after
trigger time).
MASTER-OAFA Very Wide Field Camera detected OT in Swift GRB 191221B
(Laha et al GCN 26534; Lipunov et al., GCN 26537; Kuin, GCN 26538;
Gokuldass et al., GCN 26551; Vielfaure et al., GCN 26553;) error-box
at coordinates at 2019-12-21 20:41:35 UT (142 s after trigger time).
with m_OT~10.5 mag.
The observation and reduction will be continued. The message may be cited.
GCN Circular 26553
Subject
GRB 191221B: VLT/X-shooter redshift
Date
2019-12-22T10:58:41Z (6 years ago)
From
Maryam Arabsalmani at University of Melbourne <mar.arabsalmani@gmail.com>
Title: GRB 191221B: VLT/X-shooter redshift
J.-B. Vielfaure (CNRS, Paris Obs.), M. Arabsalmani (ICRAR/UWA), K. E.
Heintz (Univ. Iceland), N. R. Tanvir (Univ. Leicester), A. de Ugarte
Postigo (HETH/IAA-CSIC), D. B. Malesani (DTU Space), J. P. U. Fynbo
(DAWN/NBI), K. Wiersema (Univ. Warwick), S. D. Vergani (CNRS, Paris Obs.),
D. Xu (NAO/CAS), G. Pugliese (Univ. Amsteram), S. Schulze (WIS), D.
Burgarella (AMU, CNRS, CNES, LAM), report on behalf of the Stargate
collaboration:
We observed the optical afterglow of GRB 191221B (Laha et al., GCN 26534;
Longo et al., GCN 26549; Lipunov et al., GCN 26537). using the ESO VLT UT2
(Kueyen) equipped with the X-shooter spectrograph. Our spectra cover the
wavelength range 3000-21000 AA, and consist of 2 exposures by 600 s each.
The observation mid time was 2019 Dec 22.2707 UT (9.843 hr after the GRB).
In a 15 s image taken with the acquisition camera on Dec 22.2592 UT, we
detect the optical afterglow, for which we measure a magnitude r = 17.13 +-
0.01 AB (calibrated against nearby stars from the Skymapper catalog; Wolf
et al. 2018, PASA, 35, 010; https:doi.org/10.4225/41/593620ad5b574).
We detect several absorption profiles in the GRB spectrum including MgII,
MgI, SiII, CIV, AlII, NiII, and FeII lines. From these metal lines we infer
a redshift z=1.148 for the GRB, consistent with the redshift reported by
Swift/UVOT tram (GCN 26538). We also detect the MgII absorption profile
corresponding to an intervening system at z=0.961.
We acknowledge excellent support from the ESO observing staff in Paranal,
in particular Pascale Hibon, Francisco Belmar, and Trystyn Berg.
GCN Circular 26552
Subject
GRB 191221B: Correction to GCN26551 - VIRT OT observation
Date
2019-12-22T10:39:57Z (6 years ago)
From
Priyadarshini Gokuldass at U. of the Virgin Islands <priyadass.94@gmail.com>
P. Gokuldass (UVI), D. Morris (UVI), N. Orange (OrangeWave Innovative
Science, LLC), A. Cucchiara (College of Marin), R. Strausbaugh (UVI)
report:
We observed the field of GRB191221B (Laha et al, GCN 26534) with the
0.5m Virgin Island Robotic Telescope (VIRT) at the University of the
Virgin Islands' Etelman Observatory on 12-22-2019 starting at 07:16:00
UT (T+10.6hrs). We performed a series of 50x10s exposures in R-band
filter. The weather conditions were clear during the hours of
observation and the
zenith angle at the start of observations was 60 degrees and rising.
We observed the enhanced Swift-XRT position with a 20'x20' field of
view.
We clearly detect the uncatalogued source within the enhanced
Swift-XRT error radius that was reported by Lipunov et al (GCN 26537).
We measure the source with a magnitude:
R = 16.7 + / - 0.1
The magnitude is estimated from comparison to nearby USNO B1 stars and
is not corrected for Galactic extinction. The VIRT is still in the
commissioning phase.
Observations and data analysis are ongoing.
This work is supported by NASA-MUREP-MIRO grant NNX15AP95A and NSF-EiR
grant 1901296. This message can be cited.
GCN Circular 26551
Subject
GRB 191221B: VIRT Optical Upper Limits
Date
2019-12-22T10:12:13Z (6 years ago)
From
Priyadarshini Gokuldass at U. of the Virgin Islands <priyadass.94@gmail.com>
P. Gokuldass (UVI), D. Morris (UVI), N. Orange (OrangeWave Innovative
Science, LLC), A. Cucchiara (College of Marin), R. Strausbaugh (UVI) report:
We observed the field of GRB191221B (Laha et al, GCN 26534) with the 0.5m
Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 12-22-2019 starting at 07:16:00 UT
(T+10.6hrs). We performed a series of 50x10s exposures in R-band filter.
The weather conditions were clear during the hours of observation and the
zenith angle at the start of observations was 60 degrees and rising. We
observed the enhanced Swift-XRT position with a 20'x20' field of view.
We clearly detect the uncatalogued source within the enhanced Swift-XRT
error radius that was reported by Lipunov et al (GCN 26537). We measure the
source with a magnitude:
R = 16.7 �� 0.1
The magnitude is estimated from comparison to nearby USNO B1 stars and is
not corrected for Galactic extinction. The VIRT is still in the
commissioning phase.
Observations and data analysis are ongoing.
This work is supported by NASA-MUREP-MIRO grant NNX15AP95A and NSF-EiR
grant 1901296. This message can be cited.
GCN Circular 26549
Subject
GRB 191221B: AGILE/MCAL observations
Date
2019-12-22T09:23:58Z (6 years ago)
From
Francesco Longo at U of Trieste,INFN Trieste <franzlongo1969@gmail.com>
F. Longo (UniTS and INFN Trieste), M. Pilia (INAF/OA-Cagliari),
F. Verrecchia (SSDC, and INAF/OAR) , A. Ursi (INAF/IAPS),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano
(INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR),
A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna),
M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi),
report on behalf of the AGILE Team:
The AGILE Mini-CALorimeter (MCAL) detected the long GRB191221B at
T0 = 2019-12-21 20:39:11.42 (+/- 0.01 s) already detected by Swift
(Laha et al., 2019; GCN #26534).
In the MCAL energy range (0.4-100 MeV), the burst lasted about ~15 s
and released a total number of ~12000 counts over a background rate of 650 Hz.
The light curve shows several peaks and can be found at
http://www.agilescienceapp.it/notices/GRB_065726_504045551.415264.png.
The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive
in the energy range 0.4-100 MeV. Additional analysis of AGILE data is
in progress.
GCN Circular 26540
Subject
GRB 191221B: Enhanced Swift-XRT position
Date
2019-12-22T03:10:37Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1950 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 191221B, 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 = 154.82992, -38.15759 which is equivalent
to:
RA (J2000): 10h 19m 19.18s
Dec (J2000): -38d 09' 27.3"
with an uncertainty of 1.7 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 26538
Subject
GRB 191221B: Swift/UVOT redshift
Date
2019-12-22T01:33:28Z (6 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT obtained a 49s grism spectrum of GRB 191221B
242 s after the BAT trigger (Laha et al., GCN Circ. 26534).
The spectrum shows a clear break at 2008 Angstrom, suggesting
a redshift of z=1.19. At that redshift, the line of He II 1640A is well
defined
and N II 2143A is present, as well as possibly N V at 1243 A.
GCN Circular 26537
Subject
GRB 191221B: MASTER OT detection
Date
2019-12-21T21:44:15Z (6 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(Lomonosov Moscow State University, SAI, Physics Department),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
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),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State
University)
MASTER auto-detection system discovered OT in Swift GRB 191221B (Laha et
al GCN 26534) error-box
at coordinates
RA,Dec(2000)=10h 19m 19.24s , -38d 09m 28s.7
with quick decay with m_OT=14.4 at 2019-12-21 21:07:33 UT
The observation and reduction will be continued. The message may be cited.
GCN Circular 26536
Subject
Swift GRB 191221B: Global MASTER-Net observations report
Date
2019-12-21T21:27:29Z (6 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 191221B ( S Laha et al., GCN 26534) errorbox 1677 sec after notice time and 1700 sec after trigger time at 2019-12-21 21:07:33 UT, with upper limit up to 17.0 mag. The observations began at zenith distance = 69 deg. The sun altitude is -30.6 deg.
The galactic latitude b = 16 deg., longitude l = 273 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1234924
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
1790 | MASTER-SAAO | P\ | 180 | 16.0 |
1991 | MASTER-SAAO | P\ | 180 | 16.7 |
2192 | MASTER-SAAO | P\ | 180 | 16.6 |
2394 | MASTER-SAAO | P\ | 180 | 17.0 |
The observation and reduction will continue.
The message may be cited.
GCN Circular 26534
Subject
GRB 191221B: Swift detection of a burst and a very bright optical candidate
Date
2019-12-21T21:00:24Z (6 years ago)
From
Sibasish Laha at GSFC <sib.laha@gmail.com>
S Laha (GSFC/UMBC/CRESST), S. D. Barthelmy (GSFC), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and
K. K. Simpson (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 20:39:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 191221B (trigger=945521). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 154.832, -38.141 which is
RA(J2000) = 10h 19m 20s
Dec(J2000) = -38d 08' 28"
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 15 sec. The peak count rate
was ~17000 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 20:40:39.3 UT, 86.2 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 154.8286, -38.1579 which is equivalent to:
RA(J2000) = 10h 19m 18.86s
Dec(J2000) = -38d 09' 28.4"
with an uncertainty of 6.8 arcseconds (radius, 90% containment). This
location is 61 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 91 seconds after the BAT trigger. A very bright afterglow candidate has
been found at the XRT position in the initial data products. Because of
coincidence loss we cannot calculate the magnitude accurately at this time.
No correction has been made for the expected extinction corresponding to E(B-V) of 0.08.
Burst Advocate for this burst is S Laha (sib.laha AT gmail.com).
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/)