//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31160 SUBJECT: GRB 211203A: Swift detection of a burst DATE: 21/12/03 09:33:20 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U Leicester), S. Dichiara (PSU), J.D. Gropp (PSU) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 09:02:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 211203A (trigger=1086826). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 170.174, +16.256 which is RA(J2000) = 11h 20m 42s Dec(J2000) = +16d 15' 21" 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 25 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~7 sec after the trigger. The XRT began observing the field at 09:03:56.8 UT, 78.5 seconds after the BAT trigger. No source was detected in 2 s of promptly downlinked data, which covered 93% of the BAT error circle. We are waiting for the full dataset to detect and localise the XRT counterpart. UVOT took a finding chart exposure of 150 seconds with the White filter starting 81 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 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT 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 0.023. Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31163 SUBJECT: Fermi GBM Upper limits for GRB 211203A DATE: 21/12/03 17:30:32 GMT FROM: Christian Malacaria at NASA-MSFC/USRA C. Malacaria (USRA) reports on behalf of the Fermi-GBM Team: Swift/BAT detected GRB 211203A at 09:02:38 UT (GCN 31160). There was no Fermi-GBM onboard trigger around the event. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no counterparts. The GBM targeted search [1], the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around the Swift/BAT time. From this search, no significant signal was found related to GRB 211203A. We set upper limits on impulsive gamma-ray emission. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------------- 0.128 s: 4.7 9.2 17.0 1.024 s: 1.6 3.8 8.2 8.192 s: 0.4 0.9 2.0 These results are preliminary. [1] Goldstein et al. 2019 arXiv:1903.12597 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31164 SUBJECT: Swift GRB 211203A: Global MASTER-Net observations report DATE: 21/12/03 17:40:08 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the Swift GRB 211203A ( P. A. Evans et al., GCN 31160) errorbox 27509 sec after notice time and 28199 sec after trigger time at 2021-12-03 16:52:37 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 70 deg. The sun altitude is -56.8 deg. The galactic latitude b = 67 deg., longitude l = 237 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1802853 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 28289 | MASTER-Amur | C | 180 | 18.5 | 28896 | MASTER-Amur | C | 180 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31165 SUBJECT: Swift Trigger 1086826 (possible GRB 211203A) is likely not an astrophysical event DATE: 21/12/03 17:57:24 GMT FROM: Tyler Parsotan at UMBC/GSFC/CRESST II T. Parsotan (GSFC/UMBC), 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 full data set from recent downlinks, we report further ground data analysis for Swift trigger 1086826 (Evans, et al., GCN Circ. 31160). The BAT analysis uses data from T-50 to T+250 sec. The BAT image significance is 3.9 sigma (15-350 keV). Also, the mask-weighted light curve does not show anything significant and there is no identified source in the ground analysis of the scaled map. We therefore conclude that this event is likely due to noise and is not an astrophysical event.