GRB 231205B
GCN Circular 35403
Subject
GRID detection of GRB 231205B
Date
2023-12-19T12:35:19Z (2 years ago)
From
GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>
Via
Web form
Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration:
GRID-03B and GRID-04, onboard the same CubeSat, report the detection of the long-duration GRB 231205B, which was also detected by Swift/BAT, GECAM-B, and AGILE(GCN Circular 35269, 35279, 35295).
The event was triggered with GRID on 2023-12-05 at 16:43:49 UTC. The GRID light curve shows a double-pulse temporal structure. The measured burst duration (T90) in the 30-2000 keV range is approximately 40.2 ± 3.0 seconds.
The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB231205B/GRID_231205B_ltcv.pdf.
GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.
GCN Circular 35372
Subject
GRB 231205B: VZLUSAT-2 detection
Date
2023-12-16T11:18:20Z (2 years ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration.
The long duration GRB 231205B (Swift/BAT detection: GCN 35269; GECAM-B detection: GCN 35279; AGILE detection: GCN 35295; Konus/WIND detection at 2023-12-05 16:43:58.336 UT) was detected by the GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).
The data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2023-12-05 16:43:57 UTC. The T90 duration is 31 s (29 s) and the significance during T90 reaches 14 sigma (12 sigma) for detector unit no. 0 (no. 1).
The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB231205B_GCN_VZLUSAT2.pdf
All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.
GCN Circular 35308
Subject
GRB231205B: Swift/UVOT Upper Limits
Date
2023-12-08T17:38:53Z (2 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
Via
Web form
M. H. Siegel (PSU) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 231205B
216 s after the BAT trigger (Evans et al., GCN Circ. 35269).
No optical afterglow consistent with the XRT position
(Osborne et al. 35275) 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 237 387 147 >21.3
white 237 536 167 >21.3
v 216 414 33 >18.6
b 492 512 19 >19.6
u 468 487 19 >18.2
w1 443 463 19 >19.3
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.204 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 35303
Subject
GRB 231205B: Swift-BAT refined analysis
Date
2023-12-07T14:01:00Z (2 years ago)
From
Tyler Parsotan at NASA GSFC <tyler.parsotan@nasa.gov>
Via
email
T. Parsotan (GSFC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU) (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 231205B (trigger #1200812)
(Evans, et al., GCN Circ. 35269). The BAT ground-calculated position is
RA, Dec = 54.151, 27.150 deg which is
RA(J2000) = 03h 36m 36.3s
Dec(J2000) = +27d 09' 00.7"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.
The mask-weighted light curve shows a strong peak near the time of trigger.
There is also emission prior to the main peak of the lightcurve at ~T-30 sec.
T90 (15-350 keV) is 46.94 +- 7.84 sec (estimated error including systematics).
The time-averaged spectrum from T-29.66 to T+54.16 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.38 +- 0.05. The fluence in the 15-150 keV band is 7.4 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-5.04 sec in the 15-150 keV band
is 7.1 +- 0.4 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/1200812/BA/ <http://gcn.gsfc.nasa.gov/notices_s/1200812/BA/> <http://gcn.gsfc.nasa.gov/notices_s/1200812/BA/> <http://gcn.gsfc.nasa.gov/notices_s/1200812/BA/>>
GCN Circular 35302
Subject
GRB 231205B: 1.3m DFOT Optical upper limit
Date
2023-12-07T13:20:11Z (2 years ago)
From
Amit Kumar Ror at ARIES <mitturor77894@gmail.com>
Via
email
Amit K. Ror, Rahul Gupta, Amar Aryan, and Shashi B. Pandey (ARIES) report:
We observed the field of GRB 231205B detected by Swift (Evans et al. 2023,
GCN 35269) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located
at the Devasthal Observatory of the Aryabhatta Research Institute of
Observational Sciences (ARIES), India. The observations were started on
2023-12-06 at 13:19:13 UT, i.e., ~ 0.86 days after the BAT trigger. We have
taken multiple frames with an exposure time of 300 s in the R filter. We
stacked the images after the alignment. We did not detect optical afterglow
in our stacked image within the enhanced Swift-XRT observation error box
(Osborne et al., 2023, GCN 35275). We obtain the following preliminary
3-sigma upper limit in the stacked image:
Date Start_UT T_start-T0 (days) Filter Exp time (s) Limiting magnitude
=========================================================
2023-12-06 13:19:13 ~0.86 R 300*36 > 22.6
Our non-detection is consistent with Odeh et al. 2023, GCN 35270;
Strausbaugh et al. 2023, GCN 35278; Jiang et al. 2023, GCN 35280; Jiang et
al. 2023, GCN 35281; Gendre et al. 2023, GCN 35282; Sasada et al. 2023, GCN
35284; Adami et al. 2023, GCN 35286; Komesh et al. 2023, GCN 35287; Brivio
et al. 2023, GCN 35289; Malenakova et al. 2023, GCN 35292; and Pankov et
al. 2023, GCN 35299
The magnitude is not corrected for the Galactic extinction in the direction
of the burst. Photometric calibration is performed using the standard stars
from the USNO-B1.0 catalog. This circular may be cited.
GCN Circular 35299
Subject
GRB 231205B: optical upper limit in TSHAOand AbAO
Date
2023-12-07T04:13:53Z (2 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), I. Reva (FAI), R. Inasaridze (AbAO), A. Pozanenko (IKI), S. Belkin (IKI, HSE) report on behalf of GRB-IKI-FuN:
We observed the field of GRB 231205B (Evans et al, GCN 35269; Liu & Xiong, GCN 35279) with Zeiss-1000 telescope of Tien-Shan Observatory (TSHAO), and AS-32 telescope of Abastumani Observatory (AbAO). No new optical sources have been found at the enhanced XRT position (Osborne et al, GCN 35275) in our observations, which is consistent with results reported early (Odeh et al, GCN 35270; Strausbaugh & Cucchiara, GCN 35278; Jiang et al, GCN 35280; Jiang et al, GCN 35281; Gendre et al, GCN 35282; Sasada et al, GCN 35284; Adami et al, GCN 35286; Komesh et al, GCN 35287; Brivio et al, GCN 35289; Malenakova et al, GCN 35292). Preliminary photometry is following:
Date UT start t-T0 Exp. Filter OT Err. UL Telescope
(mid, days) (s) (3sigma)
2023-12-05 16:43:59 0.0208333 30x120 R n/d n/d 22.0 Zeiss-10000
2023-12-05 17:16:09 0.0315857 59x60 R n/d n/d 19.6 AS-32
GCN Circular 35295
Subject
GRB 231205B: AGILE detection
Date
2023-12-06T21:37:52Z (2 years ago)
From
Claudio Casentini at INAF-IAPS <claudio.casentini@inaf.it>
Via
Web form
C. Casentini (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS), L. Baroncelli, A. Bulgarelli, A. Ciabattoni,
A. Di Piano, V. Fioretti (INAF/OAS-Bologna), G. Panebianco (Univ. Bologna - INAF/OAS Bologna), N. Parmiggiani (INAF/OAS-Bologna), F. Lucarelli (SSDC, and INAF/OAR), P.W. Cattaneo (INFN Pavia), F. Longo (Univ. Trieste, and INFN Trieste), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), A. Ursi (ASI and INAF/IAPS), I. Donnarumma, E. Menegoni (ASI),
A. Giuliani (INAF/IASF-Mi), F. Cutrona (Univ. Milano Bicocca) and P. Tempesta (TeleSpazio) report on behalf of the AGILE Team:
The AGILE satellite detected the GRB 231205B at T0 = 2023-12-05 16:43:59 s (UTC), reported by Swift (GCNs #35269, #35275, #35291) and GECAM-B (GCN #35279).
The burst is clearly visible in the AGILE scientific ratemeters of the MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors. The event lasted about 18 s and it released a total number of 11057 counts in the MCAL detector (above a background rate of 539 Hz) and 54466 counts in the AC-Top detector (above a background rate of 2889 Hz).
In the scientific ratemeters of the AC-Top detector is visible a GRB precursor, centered around -25 s to the Swift T0 and lasting 10 seconds.
The AGILE ratemeters light curves can be found at: http://www.agilescienceapp.it/notices/GRB231205B_AGILE_RM_ND.png
Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN Circular 35292
Subject
GRB 231205B: Ondrejov D50 optical upper limit
Date
2023-12-06T18:45:19Z (2 years ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
Via
legacy email
Alzbeta Malenakova, Martin Jelinek, Jan Strobl, Rene Hudec,
Cyril Polasek (ASU CAS Ondrejov, CZ),
and Sergey Karpov (Institute of Physics, Prague, CZ)
report:
The 50 cm robotic telescope D50 located at Ondrejov
observatory (Czech Republic) reacted robotically to the
Swift-BAT alert of GRB 231205B (Evans et al., GCNC 35269),
reported also by GECAM-B (Liu et al., GCNC 35279), obtaining a
series of 20 s unfiltered images starting at 16:45:46 UT, i.e.
107 s post trigger.
We do not detect any new optical source in the XRT error box
(neither any new or strongly variable source in the BAT
errorbox) in single images (detection limit r' > 18.7) nor in
a combined 30 x 20 s frame (mean exp time 290 s post trigger,
with a limit r' > 21.0) similarly to Odeh et al. (GCNC 35270),
Jiang et al. (GCNC 35280), Jiang et al. (GCNC 35281) and
Komesh et al. (GCNC 35287). All magnitudes are calibrated
with Atlas Refcat 2.0 (Tonry et al., ApJ 867, 105, 2018).
GCN Circular 35291
Subject
GRB 231205B: Swift-XRT refined Analysis
Date
2023-12-06T15:26:36Z (2 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
S. Dichiara (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U.
Leicester), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M.
Perri (SSDC & INAF-OAR), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto)
and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 6.5 ks of XRT data for GRB 231205B, from 224 s to 68.4
ks after the BAT trigger. The data comprise 3 s in Windowed Timing
(WT) mode (taken while Swift was slewing), with the remainder in Photon
Counting (PC) mode.
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.27 (+0.04, -0.05), followed by a break at T+6137 s to
an alpha of 1.32 (+/-0.08).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.06 (+/-0.10). The
best-fitting absorption column is 4.5 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.5 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 (6.2 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 4.5 (+/-0.5) x 10^21 cm^-2
Galactic foreground: 1.5 x 10^21 cm^-2
Excess significance: 9.6 sigma
Photon index: 2.06 (+/-0.10)
If the light curve continues to decay with a power-law decay index of
1.32, the count rate at T+24 hours will be 0.063 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.3 x
10^-12 (3.9 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/01200812.
This circular is an official product of the Swift-XRT team.
GCN Circular 35289
Subject
GRB 231205B: REM optical/NIR upper limits
Date
2023-12-06T14:26:13Z (2 years ago)
From
Riccardo Brivio <riccardo.brivio@inaf.it>
Via
Web form
R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) on behalf of the REM team, report:
We observed the field of GRB 231205B (Evans et al., GCN 35269) 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 06 at 00:32:29 UT (i.e. about 7.81 hours after the Swift trigger) and lasted for about 1 hour.
From preliminary analysis, we do not find any source at the enhanced XRT position (Osborne et al., GCN 35275), down the the following 3 sigma upper limits:
r > 20.4 (AB; calibrated against the Pan-STARRS catalogue)
at a mid time of t-t0 ~ 8.54 h after the GRB trigger;
H > 17.8 (Vega; calibrated against the 2MASS catalogue)
at a mid time of t-t0 ~ 8.24 h after the GRB trigger.
GCN Circular 35287
Subject
GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
Date
2023-12-06T09:54:28Z (2 years ago)
From
Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh@nu.edu.kz>
Via
Web form
T. Komesh (NU), B. Grossan (UCB, NU), Zh. Maksut (NU), Zh. Abdullayev (NU), M. Krugov (FAI) and E. Abdikamalov (NU) report on behalf of the Energetic Cosmos Laboratory:
The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB 231205B, 10 s after receipt an automated GCN / BAT position alert, observing in Sloan g', r' and i' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14).
We started observations at 16:45:33 UT on 2023-12-05, 94 s after the BAT trigger. Observations were made in clear conditions. No source consistent with the XRT (J.P. Osborne et al., GCN Circ. 35275) was detected. We report the following results:
start time t-t0(s) end time UL g' UL r' ULi' exposure_time (s)
-----------------------------------------------------------------------
16:45:33 94 16:46:29 19.9 19.5 18.3 52.5
16:46:43 164 16:49:13 20.3 19.9 19.0 150
start time is in UT. t-t0(s) gives the time since trigger, in seconds. UL i', gives the 5 sigma upper limit sensitivity in magnitudes, for images co-added to the given exposure time. The first row in the table corresponds to co-adds of an initial short exposure image sequence of 0.5 s for g' and r' (these sub-second exposures are read-noise suppressed by our EMCCD cameras, with high gain electron multiplication active; other images are taken in conventional CCD operation mode), and 7.5 s for i'. The second row corresponds to co-adds from a continuing series of 3 s exposures for g' and r', and 15 s for i'. Calibration was done with the 3 bright Pan-STARRS catalog stars on our images.
----------------------------------
NU = Nazarbayev University, Nur-Sultan, Kazakhstan
UCB = University of California, Berkeley, USA
FAI = Fesenkov Astrophysical Institute, Kazakhstan
This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14870504). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.
GCN Circular 35286
Subject
GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
Date
2023-12-06T09:41:50Z (2 years ago)
From
Christophe Adami at LAM <christophe.adami@lam.fr>
Via
Web form
C. Adami (LAM), E. Le Floc'h, D. Götz, F. Schüssler,D. Turpin (CEA Paris-Saclay), A. de Ugarte Postigo (OCA/CNRS),
S. Basa (LAM), S. D. Vergani (GEPI, Obs. de Paris), report on behalf of a larger collaboration:
We observed the field of GRB231205B (GCN 35269; Evans et al., GCN 35270, Odeh et al.) using the MISTRAL spectro-imager
mounted at the T193cm telescope at Observatoire de Haute-Provence (France) under a poor seeing of ~3arcsec.
We began our observations on 2023 05 December 20:56:18 UT (~5.2h after the trigger time) with a series of r'-band (300s +
6x720s) images. Last image was taken at 22:26:25 UT. Consistently with Evans et al. and Odeh et al., we do not detect any
credible optical counterpart to GRB231205B within the GCN 35269 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 rmeanKronmag=20.65.
Using the i-band PanStarr public image, the faintest detected object in our r-band image with a measured PanStarr magnitude is
at imeanKronmag=21.60.
We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen..
GCN Circular 35284
Subject
GRB 231205B : MITSuME Akeno optical upper limits
Date
2023-12-06T08:05:47Z (2 years ago)
From
Mahito Sasada at Tokyo Institute of Technology <sasada@hp.phys.titech.ac.jp>
Via
Web form
M. Sasada, I. Takahashi, M. Niwano, S. Sato, N. Higuchi, S. Hayatsu, H. Takei, H. Seki, Y. Yatsu and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 231205B (Evans et al., GCN 35269) with the optical three-color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50-cm telescope Akeno.
The observation started at 2023-12-05 16:46:02 UT (123 seconds after the Swift/BAT trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the enhanced Swift/XRT error region (Osborne et al., GCN 35275), consistent with other non-detections (Odeh et al., GCN 35270; Strausbaugh et al., GCN 25278; Jiang et al., GCN 35280; Jiang et al., GCN 35281, Gendre et al., GCN 35282). We obtained the 5-sigma limits of the stacked images as follows.
T0+[sec] | MID-UT | T-EXP[sec] | 5-sigma limits
------------------------------------------------------------------------------------------------
517 | 2023-12-05 16:52:36 | 100 | g'>17.2, Rc>16.6, Ic>16.2
5970 | 2023-12-05 18:23:29 | 420 | g’>17.5, Rc>17.5, Ic>17.2
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the trigger
T-EXP: Total Exposure time
We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g', Rc and Ic band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN Circular 35282
Subject
GRB 231205B: Zadko observatory - Gingin optical observations
Date
2023-12-06T07:38:19Z (2 years ago)
From
Bruce Gendre at UVI <bruce.gendre@gmail.com>
Via
legacy email
B. Gendre, E. Moore, E. Van Dongen, F. Panther,
D. Coward, J. A. Moore (OzGrav-UWA), A. Klotz (IRAP-CNRS-OMP),
and P. Thierry (AGORA),
report:
We imaged the field of GRB 231205B detected by SWIFT
(Evans et al., GCN 35269, trigger 1200812) with the
Zadko robotic telescope (D=100cm) located at Gingin, Australia.
The observations started 201.6s after the GRB trigger (126.1s
after the notice). The elevation of the field decreased from
25 degrees above horizon and weather conditions were poor,
with high altitude clouds.
The date of trigger : t0 = 2023-12-05T16:43:59.500
The first image is a 10.0s exposure in tracking mode. At the
position of the XRT afterglow (Osborne et al, GCN 35275), we
do not detect any OT with a limiting magnitude of:
t0+201.6s to t0+211.6s : R > 16.2
We co-added a series of exposures:
t0+217.3s to t0+344.2s : R > 17.2
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon=162.4895 lat=-22.7655
and the galactic extinction in R band is 0.3 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
GCN Circular 35281
Subject
GRB 231205B: Gaoyazi/GOT optical upper limit
Date
2023-12-06T06:45:03Z (2 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
email
S.Q. Jiang, S.Y. Fu, X. Liu, Z.P. Zhu, J. An, T.H. Lu, D. Xu (NAOC), L.F. Huo, M.M. Yang, S.W. Luo, Z. K. Feng (XJTS) report:
We observed the field of GRB 231205B detected by Swift (Evans et al., GCN 35269) using the GOT-0.5m telescope located at Gaoyazi, Xinjiang, China. Observations started at 16:46:51 UT on 2023-12-05, i.e., 172 s after the Swift/BAT trigger, and we obtained 5x3, 5x5, 5x10, 5x15, 5x20, 5x40, 10x60, 10x90, 10x120, 10x200 s frames with the Sloan r filter.
No optical counterpart is detected in our stacked image at the Enhanced XRT position (Osborne et al., GCN 35275), down to the following 3-sigma limiting magnitude of m(r)>21.2 @ 0.80 hr
calibrated with nearby PanSTARRS stars and the magnitude is not corrected for Galactic extinction.
GCN Circular 35280
Subject
GRB 231205B: Nanshan/HMT optical upper limit
Date
2023-12-06T06:40:55Z (2 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
email
S.Q. Jiang, S.Y. Fu, X. Liu, Z.P. Zhu, J. An, 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 231205B detected by Swift (Evans et al., GCN 35269) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 16:57:41 UT on 2023-12-05, i.e., 13.7 mins after the Swift/BAT trigger, we obtained a series of 20 s, 40 s, 60 s, 90 s, 120 s, 200 s frames without any filter.
No optical source is detected in our stacked image at the Enhanced XRT position (Osborne et al., GCN 35275), down to the 3-sigma limiting magnitude of m(r)>21.3 mag(AB) @ 0.61 hr post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter and the magnitude is not corrected for Galactic extinction.
GCN Circular 35279
Subject
GRB 231205B: GECAM-B detection of a long burst
Date
2023-12-06T05:43:25Z (2 years ago)
From
Yue Wang <m18509381757@163.com>
Via
Web form
Jia-Cong Liu , Shao-Lin Xiong report on behalf of the GECAM team:
GECAM-B was triggered in-flight by a long burst, GRB 231205B, at 2023-12-05T16:43:34.100 UTC (T0), which was also observed by Swift/BAT (GCN #35269) .
According to the realtime alert data, the GECAM-B light curve shows roughly two peaks with a total duration of ~40 sec (15-1050 keV).
The time-averaged spectrum of GECAM-B realtime data from about T0 to T0+4 s could be
adequately fit by a Band function with a fluence about 8.20E-7 erg/cm^2 in 20-1000 keV.
The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/GRB231205B_LC.png
GECAM location is consistent with that of Swift/BAT within the error.
We note that these results are based on realtime alert data and thus very preliminary. Refined analysis will be reported later.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).
GCN Circular 35278
Subject
GRB 231205B: LCOGT Optical Upper Limits
Date
2023-12-06T04:03:52Z (2 years 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 231205B field (Evans et al., GCN 35269) with the LCOGT 1-meter Sinistro instrument at the McDonald Observatory, USA site, on December 6, from 01:40 to 02:12 UT (corresponding to 8.95 to 9.48 hours from 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 a source within the Swift-XRT error region around the enhanced XRT position (Osborne et al., GCN 35275) in either band, consistent with other non-detections (Odeh et al., GCN 35270)
The following 5-sigma upper limits are calculated using the PanSTARRS catalog as reference:
r > 22.6
i > 21.9
These magnitudes are not corrected for galactic extinction.
GCN Circular 35275
Subject
GRB 231205B: Enhanced Swift-XRT position
Date
2023-12-06T00:40:47Z (2 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1474 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 231205B, 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 = 54.14875, +27.14134 which is equivalent
to:
RA (J2000): 03h 36m 35.70s
Dec (J2000): +27d 08' 28.8"
with an uncertainty of 2.0 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 35270
Subject
GRB 231205B: AKO Optical Upper Limit
Date
2023-12-05T18:46:35Z (2 years ago)
From
Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>
Via
legacy email
Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International
Astronomical Center in Abu Dhabi, UAE), and Dalya Akl (American University
of Sharjah, UAE), report:
We observed the field of GRB 231205B, which was detected by Swift/BAT (GCN
35269) with our 0.36m f/7.7 robotic telescope on December 05 starting at
17:37:44 UT (corresponding to 0.9 hours from the GRB trigger time) using an
(Ic) filter.
We obtained 17x180s images. We do not detect a credible source within the
Swift-XRT error region (Evans et al., GCN 35269). The following 5-sigma
upper limit is calculated using the ATLAS catalog as a reference: Ic =
20.0.
GCN Circular 35269
Subject
GRB 231205B: Swift detection of a burst
Date
2023-12-05T17:11:16Z (2 years ago)
From
K.L. Page at U Leicester <klp5@leicester.ac.uk>
Via
email
P. A. Evans (U Leicester), S. Dichiara (PSU),
N. J. Klingler (GSFC/UMBC/CRESSTII), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 16:43:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 231205B (trigger=1200812). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 54.154, +27.146 which is
RA(J2000) = 03h 36m 37s
Dec(J2000) = +27d 08' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single peak
structure with a duration of about 40 sec. However there
may be activity before the start of the immediately-available
data, as the burst occurred during a pre-planned slew. The peak count
rate was ~6000 counts/sec (15-350 keV), at T-3, before the
nominal trigger time.
The XRT began observing the field at 16:47:54.0 UT, 234.5 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 54.14912, 27.14099 which is equivalent
to:
RA(J2000) = 03h 36m 35.79s
Dec(J2000) = +27d 08' 27.6"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 23 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. No
spectrum from the promptly downlinked event data is yet available to
determine the column density.
UVOT took a finding chart exposure starting 237 seconds after the
BAT trigger. No credible afterglow candidate has been found in
the initial data products.
Burst Advocate for this burst is P. A. Evans (pae9 AT leicester.ac.uk).
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/)