GRB220921A

This page lists all entries on GRB220921A in GRBweb

Summary Fermi GBM IPN GCN 32567 GCN 32568 GCN 32570 GCN 32571 GCN 32572 GCN 32574 GCN 32575 GCN 32576 GCN 32577 GCN 32582 GCN 32596 GCN 32618

Summary table
Variable Value Source
GRB_name_Fermi GRB220921462
T0 11:05:59.070 UTC GCN_circulars,Fermi LAT Det
ra 66.7917° IPN
decl -40.2500° IPN
pos_error 4.17e-01° IPN
T90 209.988 s Fermi_GBM
T90_error 5.184 s Fermi_GBM
T90_start 11:06:02.143 UTC Fermi_GBM
fluence 5.67e-05 erg/cm² Fermi_GBM
fluence_error 1.74e-07 erg/cm² Fermi_GBM
T100 213.061 s
GBM_located False
mjd 59843.46248923611 GCN_circulars,Fermi LAT Det
Fermi GBM table
GRB_name_Fermi GRB220921462
trigger_name bn220921462
ra 66.8500°
decl -40.0000°
pos_error 2.53e+00°
datum 2022-09-21
t_trigger 11:05:59.071 UTC
T90 209.988 s
T90_error 5.184 s
T90_start 11:06:02.143 UTC
fluence 5.67e-05 erg/cm²
fluence_error 1.74e-07 erg/cm²
flux_1024 3.62e+01 erg/cm²/s
flux_1024_error 4.11e-01 erg/cm²/s
flux_1024_time 1.11e+01 erg/cm²/s
flux_64 4.67e+01 erg/cm²/s
flux_64_error 1.74e+00 erg/cm²/s
IPN table
GRB_name GRB220921A
ra 66.7917°
decl -40.2500°
pos_error 4.17e-01°
GCN 32567 table
GRB_name GRB220921A
GCN_number 32567
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32567 SUBJECT: GRB 220921A: Tiled Swift observations DATE: 22/09/21 18:43:03 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the Fermi/LAT GRB 220921A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00107 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the Fermi/LAT event is high: 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.
GCN 32568 table
GRB_name GRB220921A
GCN_number 32568
Detection_method Fermi LAT Det
t_trigger 11:05:59.070 UTC
ra 66.7900°
decl -40.2500°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32568 SUBJECT: GRB 220921A: Fermi-LAT detection DATE: 22/09/21 19:17:34 GMT FROM: Roberta Pillera at Politecnico and INFN Bari R. Pillera (Politecnico and INFN Bari), E. Bissaldi (Politecnico and INFN Bari), N. Di Lalla (Stanford Univ.) report on behalf of the Fermi-LAT team: At 11:05:59.07 UTC on September, 21, 2022 Fermi-LAT detected high-energy emission from GRB 220921A, which was also detected by Fermi GBM (trigger 685451164 / 220921462). The best LAT on-ground location is found to be RA, Dec = 66.79, -40.25 (J2000) with an error radius of 0.42 deg (90 % containment, statistical error only). This was 69 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. The 100 MeV - 1 GeV photon flux in the time interval 0-2000 s after the GBM trigger is (3.1 +/- 0.1)E-06 ph/cm2/s. The estimated photon index above 100 MeV is -2.1 +/- 0.3. The highest-energy photon is a 866 MeV event which is observed 935 seconds after the GBM trigger. A Swift ToO has been requested for this burst. The Fermi-LAT point of contact for this burst is Roberta Pillera (roberta.pillera@ba.infn.it). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN 32570 table
GRB_name GRB220921A
GCN_number 32570
Detection_method Fermi LAT Other
ra 66.4726°
decl -40.4057°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32570 SUBJECT: GRB 220921A: MASTER OT inside Fermi-LAT error-box DATE: 22/09/21 22:44:10 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov (Lomonosov MSU), D.A.H.Buckley (SAAO), N.Tiurina, A.Kuznetsov, O.Gress, E.Gorbovskoy, G.Antipov, P.Balanutsa, K.Zhirkov, A.Chasovnikov, D.Vlasenko, V.Senik, D.Kuvshinov, V.Topolev,Ya.Kechin, Yu.Tselik (Lomonosov Moscow State University, SAI, Physics Department), C.Francile, R. Podesta, C.Lopez, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), N.M.Budnev (ISU,API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER OT J042553.42-402420.7 discovery as possibly counterpart of GRB 220921A AT2022vjw MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 04h 25m 53.42s -40d 24m 20.7s on 2022-09-21.82255 UT during Fermi trigger 685451164 inspection(T0=2022-09-21 11:05:59.07) (Lipunov et al. GCN 32569, Fermi-LAT GCN 32568, also detected by GECAM-B) https://master.sai.msu.ru/site/master2/event.php?id=2097239 . The OT unfiltered magnitude is 17.8m (automatic), mlim=19.8. The OT is seen in 24 images. There is no minor planet at this place. We have 600 reference images without any OT since 2014, for ex., on 2018-11-12.98741 UT with unfiltered mlim=20.3m. Spectral observations are required. There is possible host galaxy in VIZIER database (DES, rmag=24.3) The message may be cited.
GCN 32571 table
GRB_name GRB220921A
GCN_number 32571
Detection_method Swift-XRT Other
ra 66.4725°
decl -40.4057°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32571 SUBJECT: GRB 220921A: Swift-XRT Observations DATE: 22/09/22 02:55:44 GMT FROM: Noel Klingler at NASA-GSFC / UMBC Swift-XRT has performed follow-up observations of the Fermi-LAT-detected burst GRB 220921A, collecting 4.1 ks of Photon Counting (PC) mode data between T0+27.4 and T0+40.7 ks. An uncatalogued X-ray source has been detected consistent with being within 17.3 arcmin from the center of the Fermi-LAT position (which is within its 90% error radius of 25.19 arcmin; Pillera et al., GCN 32568), and being consistent with the optical transient detected by MASTER (Lipunov et al., GCN 32570). The source's peak flux (8.6 (+/- 1.9) * 10^-12 erg cm^-2 s^-1) is 7.6-σ above the RASS limit, and it is fading with 2.9-σ significance. Source 1: RA (J2000): 66.47255 = 04:25:53.41 Dec (J2000): -40.4057 = -40:24:20.4 Error: 3.8 arcsec (radius, 90% conf.) Count-rate: (0.20 [+/- 0.04]) ct s^-1 Distance: 17.3 arcsec from Fermi-LAT position Exposure: 1328 s (vignetting corrected) Two other uncatalogued sources were also detected within the GRB position. 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/xrt_products/TILED_GRB00107/. Further observations are pending. This circular is an official product of the Swift-XRT team.
GCN 32572 table
GRB_name GRB220921A
GCN_number 32572
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32572 SUBJECT: GRB 220921A: MeerLICHT afterglow observations DATE: 22/09/22 10:02:05 GMT FROM: Simon de Wet at UCT S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) and D.A.H Buckley (SAAO) report on behalf of the MeerLICHT consortium: Following the detection of GRB 220921A by Fermi/LAT (Pillera et al., GCN 32568), the 0.6m wide-field MeerLICHT telescope, located at Sutherland, South Africa, obtained a repeated series of 60s exposures of a field encompassing the entire LAT error box in the q,u,g,r,i,z bands following the sequence quqgqrqiqz. Observations started at 01:29:34 UT on September 22 and continued for approximately two hours. We detect the previously reported afterglow to GRB 220921A at a position consistent with the MASTER and Swift/XRT positions (Lipunov et al., GCN 32570; Kingler et al., GCN 32571) with the following AB magnitudes at a mid-time of September 22 01:46:00 UT, 0.61 days after the LAT trigger time: u = 19.28 +/- 0.14 g = 18.64 +/- 0.03 q = 18.47 +/- 0.02 r = 18.43 +/- 0.04 i = 18.25 +/- 0.05 z = 18.24 +/- 0.11 We note that the source is exhibiting fading behaviour with respect to the previously reported MASTER brightness (Lipunov et al., GCN 32570). MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.
GCN 32574 table
GRB_name GRB220921A
GCN_number 32574
Detection_method Fermi GBM Det
t_trigger 11:05:59.071 UTC
ra 66.8500°
decl -40.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32574 SUBJECT: GRB 220921A: Fermi GBM detection DATE: 22/09/22 17:01:16 GMT FROM: Elisabetta Bissaldi at INFN,Bari E. Bissaldi (Politecnico and INFN Bari) reports on behalf of the Fermi GBM Team: "At 11:05:59.071 UT on 21 September 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 220921A (trigger 685451164/ 220921462), which was also detected by Fermi-LAT (Pillera et al. 2022, GCN #32568). The on-ground calculated location, using the GBM trigger data, is RA = 66.85, DEC = -40.0 (J2000 degrees, equivalent to 04h 27m, -40d 00'), with a statistical uncertainty of 1 degree (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32]). The Fermi GBM on-ground Localization is consistent with the Fermi-LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 69 degrees. The GBM light curve consists of multiple emission episodes with a duration (T90) of about 210 s (50-300 keV). The time-averaged spectrum from T0 to T0+40 s is best fit by a Band function with Epeak = 142 +/- 4 keV, alpha = -0.90 +/- 0.02, and beta = -2.09 +/- 0.02. The event fluence (10-1000 keV) in this time interval is (5.92 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+11 s in the 10-1000 keV band is 36.2 +/- 0.4 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/"
GCN 32575 table
GRB_name GRB220921A
GCN_number 32575
Detection_method Konus-Wind Det
t_trigger 11:06:01.714 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 32575 SUBJECT: Konus-Wind detection of GRB 220921A DATE: 22/09/22 18:47:23 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, report: The bright, long-duration GRB 220921A (Fermi-LAT detection: Pillera et al., GCN Circ. 32568; Fermi-GBM detection: Bissaldi, GCN Circ. 32574) triggered Konus-Wind at T0=39961.714 s UT (11:06:01.714). The burst light curve shows the bright multipeaked initial emission episode which starts at ~T0-3.7 s and ends at ~T0+38 s, followed by a weaker episode at T0+220 s. The total duration of ~231 s. The emission is seen up to ~8 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB220921_T39961/ As observed by Konus-Wind, the burst had a fluence of 9.71(-2.95,+2.35)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+9.216 s, of 1.44(-0.25,+0.26)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+257.536 s) is best fit in the 20 keV - 8 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.88(-0.47,+0.67), the high energy photon index beta = -2.07(-0.50,+0.15), the peak energy Ep = 126(-36,+85) keV (chi2 = 93/78 dof). The spectrum near the maximum count rate (measured from T0+6.656 to T0+11.776 s) is best fit in the 20 keV - 8 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.89(-0.14,+0.20), the high energy photon index beta = -2.26(-0.19,+0.14), the peak energy Ep = 203(-35,+36) keV (chi2 = 106/78 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 32576 table
GRB_name GRB220921A
GCN_number 32576
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32576 SUBJECT: GRB 220921A: DDOTI Detection of the Afterglow DATE: 22/09/23 14:19:41 GMT FROM: Alan M Watson at UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Simone Dichiara (PSU), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl Lopez (UNAM), Margarita Pereyra (UNAM), and Eleonora Troja (GSFC/UMD) report: We observed the field of the Fermi/LAT GRB 220921A (Pillera et al., GCN Circ. 32568) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) from 2022-09-23 11:51 to 12:24 UTC (48.75 to 49.30 hours after the trigger) obtaining 2040 seconds of exposure. At the position of the OT detected by MASTER-Net (Lipunov et al., GCN Circ. 32570) we detect a source with w = 19.31 +/- 0.13. We calibrate our photometry against the APASS catalog. The afterglow has continued to fade from the observations reported by Lipunov et al. (GCN Circ. 32570) and de Wet et al. (GCN Circ. 32572). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Martir.
GCN 32577 table
GRB_name GRB220921A
GCN_number 32577
Detection_method Optical
ra 66.4726°
decl -40.4056°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32577 SUBJECT: GRB 220921A: ALMA detection DATE: 22/09/23 16:37:36 GMT FROM: Tanmoy Laskar at U of Bath T. Laskar (University of Utah), K. D. Alexander (University of Arizona), E. Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong (Northwestern University), R. Margutti (UC Berkeley), C. G. Mundell (University of Bath), and P. Schady (University of Bath) report on behalf of a larger collaboration: "We observed GRB 220921A (Pillera et al., GCN 32568) with the Atacama Large Millimeter/Submillimeter Array (ALMA) at 97.5 GHz beginning on 2021 September 23 08:04 UT (45 h after the burst). Preliminary analysis reveals a mm source with flux density of ~ 0.7 mJy at position: RA (J2000) = 04:25:53.42 Dec (J2000) = -40:24:20.25 with uncertainty ~ 0.01" in each coordinate, consistent with the X-ray position (N. Klinger, GCN 32571) and optical position (Lipunov et al., GCN 32570). Further observations are planned. We thank the JAO staff, AoD, P2G, and the entire ALMA team for their help with these observations."
GCN 32582 table
GRB_name GRB220921A
GCN_number 32582
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32582 SUBJECT: GRB 220921A: further MeerLICHT observations DATE: 22/09/25 15:34:07 GMT FROM: Simon de Wet at UCT S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) and D.A.H Buckley (SAAO) report on behalf of the MeerLICHT consortium: The 0.6m wide-field MeerLICHT telescope obtained a total of six 300s exposures in the qugrizq bands in order to monitor the evolving afterglow of GRB 220921A. Observations started at 00:34:09 UT on September 24, approximately 2.56 days post-trigger. We detect the afterglow with a SNR > 5 in the qugri bands and with a SNR of 3.8 in the z band. We report the following magnitudes: u = 20.63 +/- 0.21 g = 20.52 +/- 0.10 q = 20.23 +/- 0.04 r = 20.16 +/- 0.10 i = 20.24 +/- 0.14 z = 19.91 +/- 0.28 We note that the source is continuing to fade. MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.
GCN 32596 table
GRB_name GRB220921A
GCN_number 32596
Detection_method Fermi LAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32596 SUBJECT: GRB 220921A: LCOGT Optical Observations DATE: 22/09/27 18:10:04 GMT FROM: Robert Strausbaugh at University of Minnesota R. Strausbaugh (University of Minnesota), A. Cucchiara (College of Marin) report on behalf of a larger collaboration: We observed the Fermi-LAT detection GRB 220921A (Pillera et al., GCN 32568) field with the Las Cumbres Observatory Global Telescope Network (LCOGT) 1-meter Sinistro instrument at the South African Astronomical Observatory site, on September 22, from 00:18 to 00:45 (corresponding to 13.22 to 14.57 hours from the GRB trigger time) with the Bessel I and R filters. We performed a series of 3x300s exposures in R and I bands. We detect the MASTER optical afterglow candidate (Lipunov et al., GCN 32570), in both bands, consistent with other optical detections (de Wet et al., GCN 32572; Watson et al., GCN 32576). The following magnitudes are calculated using the USNO-B1 catalog as reference: R= 18.02 +/- 0.27 I= 17.78 +/- 0.36 We also observed the afterglow of GRB 220921A with the LCOGT 1-meter Sinistro instrument at the Cerro Tololo Interamerican Observatory, Chile site, on September 23, from 04:50 to 05:18 (corresponding to 41.75 to 42.22 hours from the GRB trigger time) with the Bessel I and R filters. We performed a series of 3x300s exposures in R and I bands. We detect the MASTER optical afterglow candidate (Lipunov et al., GCN 32570) in both bands. The following magnitudes are calculated using the USNO-B1 catalog as reference: R= 19.26 +/- 0.34 I= 19.03 +/- 0.39 These magnitudes are not corrected for galactic extinction. Further observations are planned.
GCN 32618 table
GRB_name GRB220921A
GCN_number 32618
Detection_method Optical
ra 66.4725°
decl -40.4057°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32618 SUBJECT: GRB 220921A: ATCA detection of radio counterpart DATE: 22/10/03 06:49:53 GMT FROM: James Leung at U of Sydney/VAST James Leung (University of Sydney/CSIRO), Ziteng Wang (University of Sydney/CSIRO), Emil Lenc (CSIRO), Tara Murphy (University of Sydney) The Australia Telescope Compact Array (ATCA) observed GRB 220921A (Pillera et al., GCN 32568) at multiple frequencies starting on 2022 September 28, from 16:30 to 21:00 UTC (7.2 to 7.4d post-trigger). We detect a radio source in all bands at the position: RA (J2000) = 04:25:53.4 Dec (J2000) = -40:24:20.5 with uncertainty ~0.5" in each coordinate, which is consistent with the MASTER optical (Lipunov et al., GCN 32570) and ALMA mm (Laskar et al., GCN 32577) candidate afterglow positions. We report our preliminary flux density measurements below: Freq (GHz) | Peak Flux Density (micro-Jy/beam) ---------------------------------------------- 5.5 | 163 +/- 19 9.0 | 364 +/- 17 16.7 | 763 +/- 50 21.2 | 988 +/- 95 Ongoing observations are planned. We thank CSIRO staff for rapidly scheduling and supporting these observations.