GRB 231216A
GCN Circular 35378
Subject
GRB 231216A: Swift detection of a burst
Date
2023-12-16T18:56:07Z (a year ago)
From
Tullia Sbarrato at INAF-OAB <tullia.sbarrato@inaf.it>
Via
email
T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), S. Dichiara (PSU),
M. Ferro (INAF-OAB), J.D. Gropp (PSU), S. Laha (GSFC/UMBC),
M. J. Moss (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL),
B. Sbarufatti (INAF-OAB) and M. H. Siegel (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:
At 18:35:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 231216A (trigger=1202749). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 39.759, +33.596 which is
RA(J2000) = 02h 39m 02s
Dec(J2000) = +33d 35' 45"
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 70 sec. The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 18:37:53.1 UT, 131.1 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 39.77287, 33.57671 which
is equivalent to:
RA(J2000) = 02h 39m 05.49s
Dec(J2000) = +33d 34' 36.2"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 80 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 https://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 8.36
x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 250 seconds with the U filter starting
191 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 33% of the
XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag.
Results from the list of sources generated on-board are not available at this
time. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.081.
Burst Advocate for this burst is T. Sbarrato (tullia.sbarrato AT inaf.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/)
GCN Circular 35381
Subject
GRB 231216A: BOOTES-2/TELMA optical upper limit
Date
2023-12-16T20:47:29Z (a year ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Via
Web form
Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, R. Sanchez-Ramirez, I. Perez-Garcia, S.-Y. Wu, S. Guziy (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC) and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report:
Following the detection of GRB 231216A by Swift (Sbarrato et al., GCNC 35378), the 0.6m BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) automatically pointed to the burst position on Dec. 16 at 18:41:57 UT (i.e. ~51 s after notice, 5.3 min after trigger). In the co-added image (28 x 10 s, clear filter), no optical afterglow is detected within the XRT position down to 20.0 mag, which is consistent with both reports from UVOT (Sbarrato et al., GCNC 35378) and MASTER (Lipunov et al. GCNC 35379).
We thank the staff at IHSM/UMA-CSIC La Mayora for their excellent support.
GCN Circular 35382
Subject
GRB 231216A: NOT optical upper limits
Date
2023-12-16T22:12:21Z (a year ago)
From
Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl>
Via
Web form
Daniele B. Malesani (DAWN/NBI and Radboud Univ.), Jacco H. Terwel (TCD and NOT), Benjamin N. Hauptmann (DTU Space and NOT) report on behalf of a larger collaboration:
We observed the position of GRB 231216A (Sbarrato et al., GCN 35378) using the Nordic Optical Telescope equipped with the ALFOSC images. Observations were carried out in the SDSS r and z filters, with an exposure time of 4x200 s in each filter. The delivered seeing in the combined images was around 1.5", and some calima affected the sky transparency.
Within (or near) the current XRT error circle, we detect no new objects down to magnitudes r > 23.5 and z > 21.5 (both AB), with mean times 2.25 and 2.44 hr after the trigger, respectively.
GCN Circular 35383
Subject
GRB 231216A: GIT optical upper limit
Date
2023-12-16T22:30:41Z (a year ago)
From
Vishwajeet Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>
Via
Web form
R. Sharma, V. Swain, V. Bhalerao (IIT Bombay), S. Barway, G. C. Anupama (IIA), K. Angail (IAO)
We observed the field of GRB 231216A detected by Swift (Sbarrato et al., GCN Circ. 35378) with 0.7m GROWTH-India Telescope (GIT). The observations started at 18:59:01.9 UT on 2023-12-16, i.e., 23 minutes after the BAT trigger. We obtained the multiple exposures of 100 and 300 sec in the g' and r' filters. In our stacked images, we did not detect the afterglow within the Swift-XRT position. The obtained upper limits follow as:
JD (mid) | t_mid-t0 (hours)| Filter | Exposure (s) | Limiting Magnitude (5 sigma) |
2460295.3278711 | 1.27 | r' | 5100 (stacked) | 22.0 |
2460295.3648310 | 2.16 | g' | 1500 (stacked) | 21.0 |
Our results are consistent with the upper limits reported by Global MASTER-Net (Lipunov et al., GCN Circ. 35379), BOOTES-2/TELMA (Hu et al., GCN Circ. 35381) and NOT (Malesani et al., GCN Circ. 35382). The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN Circular 35384
Subject
GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
Date
2023-12-16T23:40:34Z (a year ago)
From
Christophe Adami at LAM <christophe.adami@lam.fr>
Via
Web form
S. Basa (OHP/Pythéas/LAM), C. Adami (Pythéas/LAM), Y. Degot-Longhi (OHP/Pythéas), A. Saccardi (GEPI, Obs. de Paris), D. Adrien, E. Le Floc'h, F. Schüssler,
D. Turpin (CEA Paris-Saclay), report on behalf of a larger collaboration:
We observed the field of GRB231216A (GCN 35378; Sbarrato et al.) using the T120cm camera at Observatoire de Haute-Provence (France).
We began our observations on 2023 16 December 21:37:24 UT (~3h after the trigger time) with a series of R-band (10x300s) images.
Last image was taken at 22:37:51 UT.
Consistently with Lipunov et al. (GCN 35379), Hu et al. (GCN 35381), Malesani et al. (GCN 35382), and Sharma et al. (GCN 35383), we did not
detect any credible optical counterpart to GRB231216A within the GCN 35378 Swift XRT error box.
Using the r-band PanStarr public image, the faintest detected object in our R-band image with a measured PanStarr magnitude is at rMeanPSFMag=22.2.
We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen.
GCN Circular 35387
Subject
GRB 231216A: Swift-BAT refined analysis
Date
2023-12-17T05:01:41Z (a year ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Via
legacy email
H. A. Krimm (NSF), S. D. Barthelmy (GSFC), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. Moss (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
T. Sbarrato (INAF-OAB), M. Stamatikos (OSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 231216A (trigger #1202749)
(Sbarrato, et al., GCN Circ. 35378). The BAT ground-calculated position is
RA, Dec = 39.778, 33.614 deg which is
RA(J2000) = 02h 39m 06.6s
Dec(J2000) = +33d 36' 48.9"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 59%.
The mask-weighted light curve shows a structure of multiple pulses.
The emission starts from T-5 s, peaks at T0 and ends at T+60 s.
T90 (15-350 keV) is 51.2 +- 3.1 sec (estimated error including systematics).
The time-averaged spectrum from T-1.12 to T+51.39 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.63 +- 0.20. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.51 sec in the 15-150 keV band
is 1.8 +- 0.3 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/1202749/BA/
GCN Circular 35388
Subject
GRB 231216A: Swift/UVOT Upper Limits
Date
2023-12-17T10:03:34Z (a year ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Via
email
N. P. M. Kuin (UCL-MSSL) and Sbarrato (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 231216A
191 s after the BAT trigger (Sbarrato et al., GCN Circ. 35378).
No optical afterglow consistent with the XRT position was 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
u_FC 191 441 246 >20.2
v 497 814 58 >18.5
b 447 1028 63 >20.0
u 191 1018 432 >20.8
w1 546 864 58 >19.5
m2 819 839 19 >18.3
w2 473 790 58 >19.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.082 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 35389
Subject
GRB 231216A: REM NIR upper limits
Date
2023-12-17T13:53:14Z (a year ago)
From
Matteo Ferro <matteo.ferro@inaf.it>
Via
Web form
M. Ferro, R. Brivio, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) on behalf of the REM team, report:
We observed the field of GRB 231216A (Sbarrato et al., GCN 35378) with the REM 60cm robotic telescope located at the ESO Observatory of La Silla (Chile). The observations were carried out in the g,r,i,z, J,H,K bands, starting on 2023 Dec 17 at 00:40:48 UT (i.e. about 6.09 hours after the Swift trigger) and lasted for about 1 hour.
From preliminary analysis, we do not find any source at the XRT position (Sbarrato et al., GCN 35378), down the the following 3 sigma upper limits:
H > 16.7 (Vega; calibrated against the 2MASS catalogue)
at a mid time of t-t0 ~ 6.52 h after the GRB trigger;
K > 16.3 (Vega; calibrated against the 2MASS catalogue)
at a mid time of t-t0 ~ 6.61 h after the GRB trigger.
GCN Circular 35390
Subject
GRB 231216A: AST3-3 YaoAn Optical Upper Limit
Date
2023-12-17T15:05:33Z (a year ago)
From
Tianrui Sun at Purple Mountain Obs,CAS <trsun@pmo.ac.cn>
Via
legacy email
Tian-Rui Sun (Purple Mountain Observatory), Yan-Long Hua, Mao-Kai Hu, Xue-Feng Wu, Lei Liu, Ke-Lai Meng, Xiao-Yan Li (Nanjing Institute of Astronomical Observation Technology),
Xiang-Yan Yuan, Lifan Wang (TAMU), Xiao-Feng Wang (Tsinghua University), Lei Hu (CMU) report on behalf the AST3 Team:
Following the detection of GRB 231216A by Swift (Sbarrato et al., GCNC 35378),
we use Antarctic Survey Telescope 3-3 at YaoAn Astronomy Observation Station (China, Yunnan) for follow-up.
Our observation started on 2023-12-16T18:44:08 (about 506 seconds after the trigger of BAT (Sbarrato et al., GCNC 35378)).
No optical source was detected within the XRT error box down to 20.7 mag in the coadded image (total 600s, g-band).
Our non-detection is consistent with the results from the UVOT (Sbarrato et al., GCN 35378), MASTER (Lipunov et al. GCN 35379),
the BOOTES-2/TELMA (Hu et al. GCN 35381), NOT (Daniele B. Malesani et al., GCN 35382) and the T120 at Observatoire de Haute-Provence (Basa et al., GCN 35384)limits.
We thank the staff at YaoAn Astronomy Observation Station for their excellent support.
GCN Circular 35391
Subject
GRB 231216A: Swift-XRT refined Analysis
Date
2023-12-17T19:18:04Z (a year ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), M. Ferro (INAF-OAB),
J. D. Gropp (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), A.P. Beardmore
(U. Leicester), J.P. Osborne (U. Leicester) and P.A. Evans report on
behalf of the Swift-XRT team:
We have analysed 6.1 ks of XRT data for GRB 231216A, from 115 s to 68.0
ks after the BAT trigger. The data comprise 8 s in Windowed Timing
(WT) mode (taken while Swift was slewing), with the remainder in Photon
Counting (PC) mode. The refined XRT position is RA, Dec = 39.7727,
+33.5764 which is equivalent to:
RA (J2000): 02 39 05.45
Dec(J2000): +33 34 35.0
with an uncertainty of 3.9 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.7 (+nan, -nan).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.1 (+0.4, -0.3). The
best-fitting absorption column is 3.2 (+1.7, -1.4) x 10^21 cm^-2, in
excess of the Galactic value of 8.4 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.7 x 10^-11 (5.7 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.2 (+1.7, -1.4) x 10^21 cm^-2
Galactic foreground: 8.4 x 10^20 cm^-2
Excess significance: 2.8 sigma
Photon index: 2.1 (+0.4, -0.3)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01202749.
This circular is an official product of the Swift-XRT team.
GCN Circular 35393
Subject
GRB 231216A: Swift-XRT refined analysis correction
Date
2023-12-17T19:53:03Z (a year ago)
From
K.L. Page at U Leicester <klp5@leicester.ac.uk>
Via
email
K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:
GCN Circular 35391 omitted the uncertainties on the light curve power-law
decay for the Swift-XRT data. The correct value is a decay index of
alpha=0.72 (+0.11, -0.09).
If the light curve continues to decay with a power-law decay index of
0.72, the count rate at T+24 hours will be 4.8 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x 10^-13
(2.8 x 10^-13) erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular 35394
Subject
GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
Date
2023-12-17T20:06:20Z (a year ago)
From
Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>
Via
Web form
Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan),
Y. Niino (Tokyo University, Institute of Astronomy),
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report:
We image the field of GRB 231216A detected by Swift Burst Alert Telescope (BAT)(trigger 1202749)
with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. Member of:
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione
The observations started at 20:15 UT of 2023/12/16, after 1,40 hours after the GRB trigger, with principal telescope SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 20 image of 60 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software
We have not detected any clearly visible sources, up to 19.5th magnitude in a sky with light clouds and gusts of wind.
Start T0+ End T0+ Rlim
20:15:25 UT 20:36:38 UT 19.5
We did not found any optical counterpart in the error box of the XRTcandidate.
T. Sbarrato et al. GCN 35378
Magnitudes were estimated with the Gaia DR2 cat. and
are not corrected for galactic dust extinction.
The message may be cited.
GCN Circular 35395
Subject
GRB 231216A: LCOGT Optical Upper Limits
Date
2023-12-18T14:33:54Z (a year ago)
From
Robert Strausbaugh at Eastern Illinois University <rstrausbaugh@eiu.edu>
Via
email
R. Strausbaugh (Eastern Illinois University), A. Cucchiara (NASA) report on behalf of a larger collaboration:
We observed the Swift GRB 231216A (Sbarrato et al., GCN 35378) field with the LCOGT 1-meter Sinistro instrument at the Teide Observatory, Tenerife site, on December 16, from 19:08 to 19:41 UT (corresponding to 0.55 to 1.10 hours after the GRB trigger time) with the sdss r and i filters.
We performed a series of 3x300s exposures in each band. We do not detect an uncataloged source within the XRT error region in either band. This result is consistent with other optcal upper limits (Hu et al., GCN 35381; Malesani et al., GCN 35382; Sharma et al., GCN 35383; Basa et al., GCN 35384; Kuin et al., GCN 35388; Sun et al., GCN 35390; Ruocco et al., 35394).
The following 5-sigma upper limits are calculated using the PanSTARRS catalog as reference:
r > 22.7
i > 22.1
These magnitudes are not corrected for galactic extinction.
GCN Circular 35396
Subject
GRB 231216A: Nanshan/HMT optical upper limit
Date
2023-12-18T14:59:03Z (a year ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
email
J. An, S.Y. Fu, S.Q. Jiang, X. Liu, Z.P. Zhu, T.H. Lu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 231216A detected by Swift (Sbarrato et al., GCN 35378) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 18:42:32 UT on 2023-12-16, i.e., 6.83 mins after the Swift/BAT trigger, and a series of 20, 40, 60, 90, 120, 200 s frames were obtained without any filter.
No optical source is detected in our stacked image at the XRT position (Sbarrato et al., GCN 35378), down to the 3-sigma limiting magnitude of m(r) > 20.2 mag (AB) @ 26.03 mins post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter. The magnitude is not corrected for Galactic extinction.
GCN Circular 35398
Subject
GRB 231216A: 10.4 m GTC optical upper limit
Date
2023-12-18T15:52:04Z (a year ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Via
Web form
Y.-D. Hu, R. Sanchez-Ramirez, A. J. Castro-Tirado, S. Guziy, M.D. Caballero-Garcia, S.-Y. Wu, E. Fernandez-Garcia, and I. Perez-Garcia (IAA-CSIC), F. Pérez-Toledo (GTC, IAC), S. B. Pandey (ARIES) and B.-B. Zhang (NJU) on behalf of a larger collaboration, report:
Following the detection of GRB 231216A by Swift (Sbarrato et al., GCNC 35378), we triggered the 10.4m Gran Telescopio de Canarias (GTC) equipped with Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) in La Palma (Spain), starting on Dec 16, 20:18 UT (~1.7 h after the trigger). No optical afterglow is indentified within the refined Swift/XRT posiion (Sbarufatti et al. GCNC 35391) which down to i>24.5 mag, which is consistent with these reports from UVOT (Kuin et al., GCNC 35388), MASTER (Lipunov et al. GCNC 35379), NOT (Malesani et al. GCNC 35382), GIT (Sharma et al. GCNC 35383), T120 (Basa et al. GCNC 35384), REM (Ferro et al. GCNC 35389), AST-3 (Sun et al. GCNC 35390), Nastro Verde Observatory (Ruocco et al. GCNC 35394), LCOGT (Strausbaugh et al. GCNC 35395) and Nanshan/HMT (An et al. GCNC 35396).
We thank the staff at GTC for their excellent support.
GCN Circular 35399
Subject
GRB 231216A: optical upper limits from the INAF Asiago Observatory
Date
2023-12-18T16:58:09Z (a year ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
Via
legacy email
A. Reguitti (INAF-OAB / INAF-OAPd), P. D'Avanzo (INAF-OAB), I. Salmaso (INAF -OAPd), E. Cappellaro (INAF -OAPd),
report on behalf of the CIBO and of the GRAWITA collaborations:
We observed the field of GRB 231216A (Sbarrato et al., GCN Circ. 35378) from the INAF - Padova Astronomical Observatory
located in Asiago (Italy) with the 1.8m Copernico telescope starting on 2023-12-16 at 20:24:48 UT (~ 1.8 hours after the burst).
The observations have been carried out with the AFOSC camera in imaging mode using the r filter.
No optical afterglow candidate is detected within the XRT error circle (Sbarufatti et al., GCN Circ .35391) down to a 3sigma
limiting magnitude of r ~ 22.0 (AB; calibrated against the PanSTARRS catalogue).
GCN Circular 35401
Subject
GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
Date
2023-12-19T11:33:18Z (a year ago)
From
Claudio Lopresti <cl3lop@gmail.com>
Via
legacy email
Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy)
Member of:
UAI/SSV - Unione Astrofili Italiani/Sezione Stelle Variabili, GRB section.
GAD - Gruppo Astronomia Digitale.
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno), Unione Astrofili Italiani (UAI)
report:
We imaged the field of GRB 231216A detected by SWIFT(trigger 1202749)
with the telescope LX200 12” of GAD Observatory, La Spezia, Italy
The observations with a series of 60 sec exposures started at 2023-12-16 23:14:43 UT, 261 min. after the GRB trigger,with a Shmidt-Cassegrain telescope D=304 mm with reducer F/D=4.75.
at the following position (+/- 2 arcsec):
RA (J2000): 02 39 05.45
Dec(J2000): +33 34 35.0
scope D=300 mm F/D=4.8.
Weather conditions were medium.
We co-added 75 exposures of 60 sec each.
Start T0+ End T0+ R lim
261 min 341 min 18
We did not found any optical counterpart in 02 39 05.45 +33 34 35.0 position and in the error box of the XRT candidate.
ref.: T. Sbarrato et al. GCN 35378
Magnitudes were estimated with the Gaia EDR3 cat. and
are not corrected for galactic dust extinction.
Reference:
https://www.parcodellestelle.com/
The message may be cited.