//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31288 SUBJECT: GRB 211223C: Swift detection of a burst DATE: 21/12/23 14:39:35 GMT FROM: David Palmer at LANL P. A. Evans (U Leicester), S. D. Barthelmy (GSFC), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (U Tampa), K. L. Page (U Leicester), D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 14:29:26 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 211223C (trigger=1090656). Swift did not slew to the burst due to a pointing constraint. The BAT on-board calculated location is RA, Dec 227.164, -26.873 which is RA(J2000) = 15h 08m 39s Dec(J2000) = -26d 52' 20" 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 20 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 23:31 UT on 2021 December 29. There will thus be no XRT or UVOT data for this trigger before this time. 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31294 SUBJECT: Swift GRB 211223C: Global MASTER-Net observations report DATE: 21/12/24 05:50:09 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), B.L.Carrasco, J.R.Valdes,V.Chavushyan, C.J.Martinez, V.M.Patino Alvarez, M.L.H.Rodriguez (INAOE, OAGH) A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the Swift GRB 211223C ( P. A. Evans et al., GCN 31288) errorbox 54750 sec after notice time and 54769 sec after trigger time at 2021-12-24 05:42:16 UT, with upper limit up to 16.4 mag. The observations began at zenith distance = 82 deg. The sun altitude is -27.6 deg. The galactic latitude b = 26 deg., longitude l = 338 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1824979 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 54860 | MASTER-IAC | C | 180 | 16.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31295 SUBJECT: GRB 211223C: BOOTES-4/MET optical upper limit DATE: 21/12/24 09:15:36 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, T.-R. Sun, A. J. Castro-Tirado, E. Fernandez-Garcia, M. D. Caballero-Garcia, R. Sanchez-Ramirez, M. A. Castro Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), S. Guziy (Univ. of Nikolaev) and D. R. Xiong, Y. F. Fan, J. M. Bai, C. J. Wang, Y. X. Xin, X. H. Zhao (Yunnan Observatories of CAS) on behalf of a larger collaboration, report: Following the detection of GRB 211223C by Swift (Evans et al. GCNC 31288), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) automatically responded to this burst starting on Dec. 23 at 21:58:25 UT (~7.5 hours after trigger). No new source is detected within the BAT error region in the co-added image (60 x 20 s, clear filter) down to 20.1 mag. We thank the staff at the Lijiang observatory for their excellent support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31297 SUBJECT: GRB 211223C: Swift-BAT refined analysis DATE: 21/12/24 14:01:07 GMT FROM: Tyler Parsotan at UMBC/GSFC/CRESST II H. A. Krimm (NSF), S. D. Barthelmy (GSFC), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (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 211223C (trigger #1090656) (Evans, et al., GCN Circ. 31288). The BAT ground-calculated position is RA, Dec = 227.165, -26.878 deg which is RA(J2000) = 15h 08m 39.7s Dec(J2000) = -26d 52' 41.0" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 32%. The BAT light curve showed a complex structure with a duration of about 20 sec. T90 (15-350 keV) is 15.00 +- 5.00 sec (estimated error including systematics). The time-averaged spectrum from T-13.01 to T+8.99 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.15 +- 0.09. The fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.01 sec in the 15-150 keV band is 3.1 +- 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/1090656/BA/