//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31171 SUBJECT: GRB 211204C: Fermi GBM Final Real-time Localization DATE: 21/12/04 21:47:28 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 21:37:00 UT on 4 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211204C (trigger 660346625.552088 / 211204901). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 346.4, Dec = 55.8 (J2000 degrees, equivalent to J2000 23h 05m, 55d 47'), with a statistical uncertainty of 1.7 degrees. The angle from the Fermi LAT boresight is 146.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211204901/quicklook/glg_skymap_all_bn211204901.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/bn211204901/quicklook/glg_healpix_all_bn211204901.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211204901/quicklook/glg_lc_medres34_bn211204901.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31172 SUBJECT: Fermi GRB 211204C: Global MASTER-Net observations report DATE: 21/12/04 22:00:08 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-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) started inspect of the Fermi GRB 211204C ( Fermi GBM team, GCN 31171) errorbox 113 sec after notice time and 142 sec after trigger time at 2021-12-04 21:39:22 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 36 deg. The sun altitude is -46.1 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 211204C errorbox 592 sec after notice time and 621 sec after trigger time at 2021-12-04 21:47:21 UT, with upper limit up to 13.2 mag. The observations began at zenith distance = 59 deg. The sun altitude is -67.2 deg. The galactic latitude b = -4 deg., longitude l = 109 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1804120 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 157 | 2021-12-04 21:39:22 | MASTER-IAC | (23h 28m 59.46s , +57d 30m 33.7s) | P| | 30 | 16.9 | 202 | 2021-12-04 21:39:22 | MASTER-IAC | (23h 28m 59.46s , +57d 30m 33.7s) | P| | 120 | 17.7 | Coadd 212 | 2021-12-04 21:40:12 | MASTER-IAC | (23h 28m 51.98s , +57d 29m 37.7s) | P| | 40 | 17.2 | 277 | 2021-12-04 21:41:12 | MASTER-IAC | (23h 28m 57.77s , +57d 29m 49.8s) | P| | 50 | 17.3 | 352 | 2021-12-04 21:42:22 | MASTER-IAC | (23h 28m 54.98s , +57d 31m 18.2s) | P| | 60 | 17.4 | 641 | 2021-12-04 21:46:41 | MASTER-IAC | (23h 02m 55.70s , +55d 44m 36.6s) | P| | 120 | 17.7 | 641 | 2021-12-04 21:46:41 | MASTER-IAC | (23h 04m 33.66s , +55d 38m 30.9s) | P- | 120 | 16.5 | 681 | 2021-12-04 21:47:21 | MASTER-Kislovodsk | (23h 05m 40.54s , +55d 45m 23.3s) | P- | 120 | 12.3 | 846 | 2021-12-04 21:47:21 | MASTER-Kislovodsk | (23h 05m 40.54s , +55d 45m 23.3s) | P- | 450 | 12.3 | Coadd 791 | 2021-12-04 21:49:01 | MASTER-IAC | (23h 02m 50.22s , +55d 44m 07.7s) | P| | 140 | 17.8 | 791 | 2021-12-04 21:49:01 | MASTER-IAC | (23h 04m 28.38s , +55d 38m 01.6s) | P- | 140 | 16.7 | 837 | 2021-12-04 21:49:42 | MASTER-Kislovodsk | (23h 05m 37.26s , +55d 46m 40.5s) | P- | 150 | 12.4 | 966 | 2021-12-04 21:51:41 | MASTER-IAC | (23h 02m 49.52s , +55d 45m 09.1s) | P| | 170 | 17.9 | 966 | 2021-12-04 21:51:41 | MASTER-IAC | (23h 04m 27.93s , +55d 39m 02.5s) | P- | 170 | 16.9 | 1022 | 2021-12-04 21:52:32 | MASTER-Kislovodsk | (23h 05m 37.19s , +55d 45m 32.4s) | P- | 180 | 13.2 | The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31173 SUBJECT: GRB 211204C: GECAM detection DATE: 21/12/05 07:11:50 GMT FROM: Y Q Zhang at IHEP Y. Q. Zhang, S. L. Xiong, C. Cai, S. Xiao, P. Zhang, C. Y. Li, S. L. Xie, X. Y. Zhao, Y. Huang, X. Y. Song, J. C. Liu, Y. Zhao, Z. W. Guo, C. Zheng, W. C. Xue, C. W. Wang, Q. B. Yi, B. X. Zhang, W. X. Peng, R. Qiao, D. Y. Guo, X. B. Li, X. Ma, L. M. Song, P. Wang, J. Wang, Z. Zhang, S. J. Zheng, W. Chen, J. J. He, G. Y. Zhao, Y. Q. Du, H. Wu, J. Liang, Q. Luo, X. L. Zhang, H. M. Zhang, Z. H. An, M. Gao, K. Gong, B. Li, C. Li, J. H. Li, X. Q. Li, Y. G. Li, X. H. Liang, X. J. Liu, Y. Q. Liu, X. L. Sun, Y. L. Tuo, J. Z. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, X. Zhou, F. J. Lu, S. N. Zhang (IHEP) report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered in-flight by a long burst, GRB 211204C, at 2021-12-04T21:37:00.250 UTC (denoted as T0), which was also observed by Fermi/GBM (GCN #31171) and INTEGRAL/SPI-ACS (TrigID #9552). GECAM alert data was downlinked to the ground through the short message service of BeiDou Navigation Satellite System (BDS) within ~60 s after T0. According to the BDS alert data, this burst mainly consists of a broad pulse with a duration of about 25 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_92353020.png Using the automatic on-ground localization pipeline with the BDS alert data, GECAM-B localized this burst to the following position (J2000): Ra: 334.1 deg Dec: 55.1 deg Err: 3.8 deg (1-sigma, statistical only) The current systematic error of location is estimated to be several degrees which could be minimized by the ongoing calibration. The GECAM preliminary location could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_skymap_bdm_92353020_V01.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). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31174 SUBJECT: GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV DATE: 21/12/05 15:40:48 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 successfully trigger on GRB 211204C (T0: 2021-12-04T21:37:00 UTC, Fermi/GBM GCN 31171, GECAM GCN 31173, INTEGRAL/SPI-ACS trig #9552). The Fermi/GBM, INTEGRAL, and GECAM notices, 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 116.1 in a 8.192 s analysis time bin. Estimated T90 in the detector is 19.5 +/- 0.1 s (15-350 keV). NITRATES strongly prefers an origin for the burst coming from outside the coded FOV, with DeltaLLHOut of -520. An out of FOV origin is consistent with the Fermi/GBM and GECAM localizations. 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: 31177 SUBJECT: IPN triangulation of GRB 211204C DATE: 21/12/07 04:14:27 GMT FROM: Anna Ridnaia at Ioffe Institute A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey teams, K. Hurley, on behalf of the IPN, A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 211204C (Fermi GBM detection: Fermi GBM team, GCN 31171; GECAM detection: Zhang et al., GCN 31173; Swift/BAT-GUANO detection: DeLaunay et al., GCN 31174) was detected by Fermi (GBM trigger 660346625), Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), GECAM-B (GRD), and Swift (BAT) at about 77820 s UT (21:37:00). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 338.952 (22h 35m 48s) +52.171 (+52d 10' 15") Corners: 338.910 (22h 35m 38s) +49.891 (+49d 53' 29") 338.806 (22h 35m 14s) +49.979 (+49d 58' 43") 339.068 (22h 36m 16s) +54.400 (+54d 24' 01") 339.176 (22h 36m 42s) +54.316 (+54d 18' 59") --------------------------------------------- The error box area is 1084 sq. armin, and its maximum dimension is 4.5 deg (the minimum one is 4.1 arcmin). The Sun distance was 105 deg. This box may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi GBM on-ground calculated localization (GCN Circ. 31171) and GECAM-B automatic on-ground localization (GCN Circ. 31173). A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB211204_T77823/IPN The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31178 SUBJECT: GRB 211204C: AstroSat CZTI detection DATE: 21/12/07 06:17:15 GMT FROM: Gaurav Waratkar at IIT,Bombay V. Prasad (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed detection of the long GRB 211204C, which was also detected by Fermi (GCN 31171), GECAM (Zhang et al., GCN 31173) and Swift/BAT-GUANO (DeLaunay et al., GCN 31174) with IPN triangulation reported (GCN 31177). The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2021-12-04 21:37:06.50 UT. The measured peak count rate associated with the burst is 426 (+57, -23) cts/s above the background in the combined data of two quadrants, with a total of 3173 (+195, -220) cts. The local mean background count rate was 500 (+2, -2) cts/s. Using cumulative rates, we measure a T90 of 13 (+2, -1) s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2021-12-04 21:37:04.16 UT. The measured peak count rate is 592 (+80, -46) cts/s above the background in the combined Veto data of four quadrants, with a total of 4150 (+285, -354) cts. The local mean background count rate was 1677 (+4, -4) cts/s. We measure a T90 of 10 (+1, -1) s from the cumulative Veto light curve. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31186 SUBJECT: GRB 211204C: Fermi GBM detection DATE: 21/12/08 13:29:44 GMT FROM: Boyan A. Hristov at UAH Boyan A. Hristov (UAH) reports on behalf of the Fermi GBM Team: At 21:37:00.55 UT on 04 December 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 211204C (trigger 660346625 / 211204901), which was also detected by GECAM-B (Zhang et al. 2021, GCN 31173), INTEGRAL SPI_ACS (trigger num. 9552), Swift/BAT-GUANO (Tohuvavohu et al., GCN 31174), AstroSat CZTI detection (Waratkar et al., GCN 31178) and was triangulated by IPN (Ridnaia et al., GCN 31177). The GECAM localization and the IPN triangulation are consistent with the GBM localization (GCN 31171). The GBM light curve consists of a single spike with a duration (T90) of about 17.41 s +/- 2.00 s (50-300 keV). The time-averaged spectrum from T0+0.003 s to T0+19.456 s is adequately fit by a Band function with Epeak = 287.90 +/- 34.30 keV, alpha = -0.71 +/- 0.09, and beta = -2.37 +/- 0.19. The event fluence (10-1000 keV) in this time interval is (2.827 +/- 0.105)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+7.040 s in the 10-1000 keV band is 19.9063 +/- 1.1 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/