//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31329 SUBJECT: GRB 211229A: Fermi GBM Final Real-time Localization DATE: 21/12/29 03:39:48 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 03:29:15 UT on 29 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211229A (trigger 662441360.901398 / 211229145). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 295.0, Dec = 22.9 (J2000 degrees, equivalent to J2000 19h 40m, 22d 53'), with a statistical uncertainty of 3.7 degrees. The angle from the Fermi LAT boresight is 94.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211229145/quicklook/glg_skymap_all_bn211229145.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/bn211229145/quicklook/glg_healpix_all_bn211229145.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211229145/quicklook/glg_lc_medres34_bn211229145.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31330 SUBJECT: Fermi GRB 211229A: Global MASTER-Net observations report DATE: 21/12/29 04:30:30 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-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 211229A ( Fermi GBM team, GCN 31329) errorbox 264 sec after notice time and 292 sec after trigger time at 2021-12-29 03:34:08 UT, with upper limit up to 16.0 mag. Observations started at twilight. The observations began at zenith distance = 77 deg. The sun altitude is -11.9 deg. The galactic latitude b = -0 deg., longitude l = 59 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1831397 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 323 | 2021-12-29 03:34:08 | MASTER-Kislovodsk | (19h 27m 54.52s , +27d 51m 45.4s) | C | 60 | 15.5 | 323 | 2021-12-29 03:34:08 | MASTER-Kislovodsk | (19h 32m 07.22s , +27d 27m 37.1s) | C | 60 | 15.7 | 403 | 2021-12-29 03:35:28 | MASTER-Kislovodsk | (19h 25m 20.18s , +25d 55m 56.8s) | C | 60 | 16.0 | 403 | 2021-12-29 03:35:29 | MASTER-Kislovodsk | (19h 29m 28.21s , +25d 31m 46.2s) | C | 60 | 16.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31331 SUBJECT: GRB 211229A: GECAM detection DATE: 21/12/29 05:33:48 GMT FROM: Guoying Zhao at IHEP G. Y. Zhao, S. L. Xiong, X. L. Zhang , S. Xiao, C. Cai, J. J. He, Y. Huang, Z. W. Guo, C. Y. Li, X. B. Li, J. C. Liu, X. Y. Song,Y. Zhao, 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, Z. Zhang,C. W. Wang, S. J. Zheng (IHEP), report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered in-flight by a long burst, GRB 211229A, at 2021-12-29T03:30:05.200 UTC (denoted as T0), which was also observed by Fermi/GBM (GCN #31329). 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 50 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_94447805.png Using the automatic on-ground localization pipeline with the BDS alert data, GECAM-B localized this burst to the following position (J2000): Ra: 302.7 deg Dec: 27.5 deg Err: 8.7 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 location is very close to SGR J1935+2154 and cannot be ruled out as originating from it. The GECAM preliminary location could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_skymap_fit_94447805.png 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: 31334 SUBJECT: GRB 211229A: Swift/BAT-GUANO arcminute localization DATE: 21/12/29 14:16:59 GMT FROM: Aaron Tohuvavohu at U Toronto Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), James DeLaunay (UAlabama), Jamie A. Kennea (PSU), report: Swift/BAT did not localize GRB 211229A onboard (T0: 2021-12-29T03:29:15 UTC, Fermi/GBM GCN 31329, GECAM GCN 31331). The Fermi 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), confidently detects the burst in a 16.384 s analysis time bin with a sqrt(TS) of 50. Estimated duration in the detector is greater than 60 s. A confident arcminute localization is found with DeltaLLHOut of 567 and a DeltaLLHPeak of 269. See Section 9.1 and Figure 20 in the NITRATES paper for brief descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. The BAT position is RA, Dec = 295.044, 23.133 deg which is RA(J2000) = 19h 40m 10.56s Dec(J2000) = +23d 07′ 58″ with an estimated uncertainty of 4 arcmin. XRT and UVOT follow-up has been requested. Results of follow-up observations will be reported in future circulars. 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: 31335 SUBJECT: GRB 211229A: Swift ToO observations DATE: 21/12/29 15:06:32 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 211229A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021475 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT-GUANO event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31340 SUBJECT: GRB 211229A: Fermi GBM observation DATE: 21/12/30 05:30:27 GMT FROM: Peter Veres at UAH P. Veres and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 03:29:15.90 UT on 29 December 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 211229A (trigger 662441360 / 211229145), which was also detected by the Swift/BAT-GUANO (Tohuvavohu et al, GCN 31334). The Fermi GBM Final Real-time Localization (GCN 31329) is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 95 degrees. The GBM light curve shows multiple pulses with a duration (T90) of about 120 s (50-300 keV). The time-averaged spectrum from T0-10 s to T0+147 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.24 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 280 +/- 27 keV. The event fluence (10-1000 keV) in this time interval is (3.07 +/- 0.11)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+53.2 s in the 10-1000 keV band is 3.74 +/- 0.28 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/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31342 SUBJECT: GRB 211229A: Swift-XRT and UVOT observations DATE: 21/12/30 17:29:06 GMT FROM: Phil Evans at U of Leicester V. D'Elia (SSDC & INAF-OAR), S. R. Oates (U.Birmingham), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Swift/BAT-GUANO-detected burst GRB 211229A (Tohuvavohu et al., GCN Circ. 31334), also detected by Fermi/GBM and GECAM (Fermi GBM team, GCN Circ. 31329, Zhao et al., GCN Circ. 31331), collecting 5.0 ks of Photon Counting (PC) mode data between T0+43.6 ks and T0+66.8 ks. Four uncatalogued X-ray sources have been detected consistent with being within 394 arcsec of the Swift/BAT-GUANO position, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below: Source 1: RA (J2000.0): 295.1317 = 19:40:31.60 Dec (J2000.0): +23.1983 = +23:11:53.8 Error: 6.3 arcsec (radius, 90% conf.) Count-rate: (3.5 [+1.3, -1.0])e-3 ct s^-1 Distance: 252 arcsec from Swift/BAT-GUANO position. Flux: (2.78 [+1.01, -0.83])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 2: RA (J2000.0): 295.0615 = 19:40:14.76 Dec (J2000.0): +23.2617 = +23:15:42.0 Error: 9.7 arcsec (radius, 90% conf.) Count-rate: (1.60 [+0.88, -0.66])e-3 ct s^-1 Distance: 398 arcsec from Swift/BAT-GUANO position. Source 5: RA (J2000.0): 295.0738 = 19:40:17.70 Dec (J2000.0): +23.1573 = +23:09:26.3 Error: 6.6 arcsec (radius, 90% conf.) Count-rate: (2.12 [+0.97, -0.76])e-3 ct s^-1 Distance: 20 arcsec from Swift/BAT-GUANO position. Flux: (1.59 [+0.72, -0.57])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 6: RA (J2000.0): 295.1187 = 19:40:28.49 Dec (J2000.0): +23.1638 = +23:09:49.7 Error: 5.3 arcsec (radius, 90% conf.) Count-rate: (2.94 [+1.13, -0.91])e-3 ct s^-1 Distance: 151 arcsec from Swift/BAT-GUANO position. An uncatalogued source was also detected, however this was too far from the GRB position to be the afterglow. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021475. No optical afterglow consistent with the GUANO position (Tohuvavohu et al., GCN Circ. 31334) 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 initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag u 43722 66830 4882 >21.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 5.811 in the direction of the burst (Schlegel et al. 1998). This circular is an official product of the Swift-XRT and UVOT team.