//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31155 SUBJECT: GRB 211201A: Fermi GBM Final Real-time Localization DATE: 21/12/01 20:50:50 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 20:42:52 UT on 1 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211201A (trigger 660084177.881018 / 211201863). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 355.4, Dec = 2.6 (J2000 degrees, equivalent to J2000 23h 41m, 2d 36'), with a statistical uncertainty of 5.0 degrees. The angle from the Fermi LAT boresight is 108.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211201863/quicklook/glg_skymap_all_bn211201863.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211201863/quicklook/glg_healpix_all_bn211201863.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211201863/quicklook/glg_lc_medres34_bn211201863.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31156 SUBJECT: Fermi GRB 211201A: Global MASTER-Net observations report DATE: 21/12/01 21:15:07 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 211201A ( Fermi GBM team, GCN 31155) errorbox 1138 sec after notice time and 1166 sec after trigger time at 2021-12-01 21:02:19 UT, with upper limit up to 12.7 mag. The observations began at zenith distance = 75 deg. The sun altitude is -68.9 deg. The galactic latitude b = -56 deg., longitude l = 92 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1801667 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1197 | 2021-12-01 21:02:19 | MASTER-Kislovodsk | (23h 49m 38.72s , +01d 09m 30.8s) | C | 60 | 12.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31158 SUBJECT: GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV DATE: 21/12/02 21:06:16 GMT FROM: Aaron Tohuvavohu at U Toronto James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Jamie A. Kennea (PSU), report: Swift/BAT did not trigger on GRB 211201A (T0: 2021-12-01T20:42:52 UTC, Fermi/GBM GCN 31155). The Fermi/GBM notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu, arXiv:2111.01769), detects the burst with a sqrt(TS) of 13.1 in a 16.384 s analysis time bin. Estimated T90 in the detector is 30.5 +/- 0.5 s (15-350 keV). NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT FOV, with a borderline DeltaLLHOut of 9.57. An out of FOV origin is more consistent with the Fermi/GBM localization, and the Fermi/GBM spectral fit (private comm.) is consistent with the best fit OFOV model from NITRATES. Therefore we think it likely that this burst originates from outside the coded FOV. See Section 9.1 and Figure 20 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31159 SUBJECT: GRB 211201A: GECAM detection DATE: 21/12/03 01:04:55 GMT FROM: Guoying Zhao at IHEP G. Y. Zhao, S. L. Xiong,X. L. Zhang, S. Xiao, Yi Zhao, C. Cai, J. J. He, Y. Huang, Z. W. Guo, C. Y. Li, X. B. Li, J. C. Liu, X. Y. Song, P. Wang, S. L. Xie, W. C. Xue, Q. B. Yi, Y. Q. Zhang, X. Y. Zhao, C. Zheng, Y. Q. Du, D. Y. Guo, J. Liang, F. J. Lu, Q. Luo, X. Ma, W. X. Peng, R. Qiao, L. M. Song, J. Wang, H. Wu, P. Zhang, S. N. Zhang, C. W. Wang,Z. Zhang, S. J. Zheng (IHEP),report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered on-ground by a long bright burst, GRB 211201A, at 2021-12-01T20:43:06.000 UTC (denoted as T0), which was also observed by Fermi/GBM (GCN #31155). This burst mainly consists of multiple pulses with duration of about 50 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/LightCurve.png GECAM location is consistent with the Fermi/GBM position within the error. Please note that all GECAM results here are preliminary. The final analysis will be published in journal papers or GECAM online catalog. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time), which was funded by the Chinese Academy of Sciences (CAS).