//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29470 SUBJECT: GRB 210211A: Fermi GBM Final Real-time Localization DATE: 21/02/11 08:50:50 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 08:43:18 UT on 11 Feb 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210211A (trigger 634725803.658592 / 210211363). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 283.8, Dec = -55.1 (J2000 degrees, equivalent to J2000 18h 55m, -55d 06'), with a statistical uncertainty of 11.8 degrees. The angle from the Fermi LAT boresight is 45.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210211363/quicklook/glg_skymap_all_bn210211363.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/bn210211363/quicklook/glg_healpix_all_bn210211363.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210211363/quicklook/glg_lc_medres34_bn210211363.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29471 SUBJECT: Swift GRB210211.36: Global MASTER-Net observations report DATE: 21/02/11 08:54:08 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, 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, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB210211.36 (trigger No 1032024,17h 57m 43.92s , -46d 17m 56.4s, R=0.05) errorbox 25 sec after notice time and 43 sec after trigger time at 2021-02-11 08:44:02 UT, with upper limit up to 15.3 mag. The observations began at zenith distance = 52 deg. The sun altitude is -17.9 deg. The galactic latitude b = -11 deg., longitude l = 346 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1544962 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 49 | MASTER-OAFA | C | 10 | 15.3 | 79 | MASTER-OAFA | C | 10 | 15.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29472 SUBJECT: GRB 210211A: Swift detection of a burst DATE: 21/02/11 09:00:56 GMT FROM: Phil Evans at U of Leicester E. Troja (NASA/GSFC/UMCP), P. A. Evans (U Leicester), H. A. Krimm (NSF), K. L. Page (U Leicester), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 08:43:18 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210211A (trigger=1032024). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 269.433, -46.299 which is RA(J2000) = 17h 57m 44s Dec(J2000) = -46d 17' 57" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 10 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~4 sec after the trigger. The XRT began observing the field at 08:44:32.2 UT, 73.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 269.4374, -46.2660 which is equivalent to: RA(J2000) = 17h 57m 44.99s Dec(J2000) = -46d 15' 57.7" with an uncertainty of 3.4 arcseconds (radius, 90% containment). This location is 119 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.24 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 8.7 (+9.04/-6.57) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 77 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 none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the expected extinction corresponding to E(B-V) of 0.126. Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). 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: 29474 SUBJECT: GRB 210211A: REM optical/NIR afterglow detection DATE: 21/02/11 11:19:34 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, S. Covino, D. Fugazza, A. Melandri (INAF-OAB) on behalf of the REM team, report: We observed the field of GRB 210211A (Troja et al., GCN Circ. 29472) with the REM 60cm robotic telescope located at the ESO premise of La Silla (Chile). The observations were performed starting on 2021 February 11 at 08:44:54 UT (i.e. 96 seconds after the burst) and were carried in the g, r, i, z, H bands simultaneously. From a preliminary analysis of the first set of images, obtained at a mid time of t-t0 = 101 s we detect in all filters an uncatalogued object at the following position: RA (J2000), Dec (J2000) = 17:57:45.67, -46:16:01.8 (+/- 0.5") with a magnitude r = 16.9 +/- 0.1 (AB; calibrated against the APASS catalogue). This source is found about 1.5 magnitudes fainter in a subsequent set of images obtained at t-t0 = 204 s. The source position lies about 8" outside the current available XRT error circle (https://www.swift.ac.uk/xrt_positions/). However, the observed brightness and rapid fading suggests that it is the optical/NIR afterglow of GRB 210211A. We also note the presence of an optical/NIR source inside the XRT error circle whose magnitude does not show significant variation in our dataset. Further analysis is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29477 SUBJECT: GRB 210211A: MASTER optical observation of REM OT DATE: 21/02/11 12:56:02 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy,N.Tiurina,P.Balanutsa,F.Balakin, V.Vladimirov, A.Kuznetsov,K.Zhirkov,D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, A.Chasovnikov,A.Pozdnyakov,V.Topolev, D.Cheryasov(Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico FelixAguilar 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 StateUniversity) MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L) automatically started (Lipunov et al. GCN 29471) Swift GRB 200211A (Troja et al. GCN 29472,Ttrigger=08:43:18UT) at 2021-02-11 08:44:02UT with 10s exposition. At the second (10s exp), third (20s exp) and fourth images we see OT, discovered by REM (D'Avanzo et al. GCN29474) The reduction of MASTER wide field and very wide field cameras images will be continued. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29478 SUBJECT: GRB 210211A: Enhanced Swift-XRT position DATE: 21/02/11 13:47:05 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 481 s of XRT Photon Counting mode data and 1 UVOT images for GRB 210211A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 269.43976, -46.26729 which is equivalent to: RA (J2000): 17h 57m 45.54s Dec (J2000): -46d 16' 02.3" with an uncertainty of 2.4 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29482 SUBJECT: GRB 210211A: Fermi GBM observation DATE: 21/02/11 20:30:18 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC), A. von Kienlin (MPE), and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 08:43:18.66 UT on 11 February 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 210211A (trigger 634725803 / 210211363) which was also detected by the Swift/BAT and Swift/XRT (E. Troja et al. 2021, GCN 29472). The Fermi GBM Final Real-time Localization (GCN 29470) is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 50.5 degrees. The GBM light curve shows multiple peaks with a duration (T90) of about 29 s (50-300 keV). The time-averaged spectrum from T0-4 s to T0+27 s is best fit by a Band function with Epeak = 95 +/- 35 keV, alpha = 2.8 +/- 3.1, and beta = -1.5 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (3.1 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.8 s in the 10-1000 keV band is 1.8 +/- 0.2 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: 29483 SUBJECT: GRB 210211A: Swift-BAT refined analysis DATE: 21/02/11 20:52:22 GMT FROM: Hans Krimm at NSF/NASA-GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+600 sec from the recent telemetry downlink, we report further analysis of BAT GRB 210211A (trigger #1032024) (Troja, et al., GCN Circ. 29472). The BAT ground-calculated position is RA, Dec = 269.408, -46.270 deg which is RA(J2000) = 17h 57m 38.0s Dec(J2000) = -46d 16' 11.0" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single broad peak starting at T-1 sec, and decaying to background by T+8 sec. T90 (15-350 keV) is 6.1 +- 0.6 sec (estimated error including systematics). The time-averaged spectrum from T-0.70 to T+5.90 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.09 +- 0.16. The fluence in the 15-150 keV band is 4.2 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+4.28 sec in the 15-150 keV band is 1.0 +- 0.2 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/1032024/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29484 SUBJECT: GRB 210211A: Swift-XRT refined Analysis DATE: 21/02/11 22:28:35 GMT FROM: Phil Evans at U of Leicester A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and E. Troja report on behalf of the Swift-XRT team: We have analysed 9.6 ks of XRT data for GRB 210211A (Troja et al. GCN Circ. 29472), from 81 s to 40.6 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 29478). The light curve can be modelled with a power-law decay with a decay index of alpha=1.15 (+0.09, -0.08). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.5 (+0.7, -0.6). The best-fitting absorption column is 6.7 (+6.5, -3.6) x 10^21 cm^-2, in excess of the Galactic value of 1.2 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (8.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.7 (+6.5, -3.6) x 10^21 cm^-2 Galactic foreground: 1.2 x 10^21 cm^-2 Excess significance: 2.5 sigma Photon index: 2.5 (+0.7, -0.6) If the light curve continues to decay with a power-law decay index of 1.15, the count rate at T+24 hours will be 7.2 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x 10^-14 (6.1 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01032024. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29485 SUBJECT: GRB 210211A: Swift/UVOT Detection DATE: 21/02/11 22:59:12 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 210211A 78 s after the BAT trigger (Troja et al., GCN Circ. 29472). A source consistent with the XRT position (Osborne et al. GCN Circ. 29478) and the REM detection (d'Avanzo et al., GCN Circ. 29474)is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 17:57:45.68 = 269.44035 (deg.) Dec (J2000) = -46:16:01.6 = -46.26711 (deg.) with an estimated uncertainty of 0.47 arc sec. (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 78 227 147 17.89 +/- 0.06 white 596 611 15 >18.6 white 5391 5587 197 >20.3 v 4239 4438 197 >19.8 b 545 565 19 >18.4 u 290 489 196 >18.6 m2 4444 4491 47 >18.3 w2 4034 4234 197 >19.4 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.127 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29515 SUBJECT: GRB 210211A: ePESSTO+ NTT optical observations DATE: 21/02/16 18:08:56 GMT FROM: Paolo D'Avanzo at INAF-OAB L. Harvey, M. Magee (TCD), P. D'Avanzo (INAF-OAB), D. B. Malesani (DTU Space), S. Prentice, M. Deckers (TCD), S. Schulze (OKC), J. Teffs (LJMU), S. Gonzalez-Gaitan (CENTRA), J. Anderson (ESO), T. Muller Bravo (Southampton), T.-W. Chen (Stockholm), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), M. Nicholl (Birmingham), O. Yaron (Weizmann), D. Young (QUB), I. Manulis (Weizmann), report: We observed the field of GRB 210211A (Fermi GBM Team, GCN Circ. 29470; Troja et al., GCN Circ. 29472) under the advanced extended Public ESO Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org ). The observations were performed on the ESO New Technology Telescope at La Silla with the EFOSC2 instrument in imaging mode on 2021-02-16 between 08:01:05 UT and 08:42:23 UT (i.e. about 4.99 days from the burst). The observations were carried out with the R filter under a seeing of about 1.9". The optical afterglow (D'Avanzo et al., GCN Circ. 29474; Lipunov et al. GCN Circ. 29477; Kuin et al., GCN Circ. 29485) is not detected down to a 3sigma limiting magnitude of R ~ 24.3 (Vega; based on preliminary photometry calibrated against the USNO B1 catalogue).