GRB210822A

This page lists all entries on GRB210822A in GRBweb

Summary IPN Swift GCN 30677 GCN 30678 GCN 30679 GCN 30680 GCN 30681 GCN 30682 GCN 30684 GCN 30687 GCN 30689 GCN 30691 GCN 30692 GCN 30693 GCN 30694 GCN 30696 GCN 30697 GCN 30701 GCN 30703 GCN 30710 GCN 30712 GCN 30713 GCN 30714 GCN 30723 GCN 30744

Summary table
Variable Value Source
T0 9:18:18 UTC GCN_circulars,Fermi LAT Det
ra 304.4375° Swift
decl 5.2834° Swift
pos_error 1.29e-04° Swift
T90 180.8 s Swift
T90_start 9:18:18 UTC Swift
fluence 2.00e-05 erg/cm² Swift
redshift 1.7360 GCN_circulars,Swift-BAT Det
T100 180.8 s
GBM_located False
mjd 59448.387708333335 GCN_circulars,Fermi LAT Det
IPN table
GRB_name GRB210822A
ra 304.4750°
decl 5.2667°
pos_error 5.00e-02°
redshift 1.7360
Swift table
GRB_name GRB210822A
t_trigger 9:18:18 UTC
ra 304.4375°
decl 5.2834°
pos_error 1.29e-04°
T90 180.8 s
fluence 2.00e-05 erg/cm²
redshift 1.7360
GCN 30677 table
GRB_name GRB210822A
GCN_number 30677
Detection_method Swift Det
t_trigger 9:18:18 UTC
ra 304.4760°
decl 5.2650°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30677 SUBJECT: GRB 210822A: Swift detection of a burst with an optical afterglow DATE: 21/08/22 09:52:13 GMT FROM: Kim Page at U.of Leicester K. L. Page (U Leicester), J.D. Gropp (PSU), N. P. M. Kuin (UCL-MSSL) and A. Y. Lien (U Tampa) report on behalf of the Neil Gehrels Swift Observatory Team: At 09:18:18 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210822A (trigger=1069788). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 304.476, +5.265 which is RA(J2000) = 20h 17m 54s Dec(J2000) = +05d 15' 54" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 30 sec. The peak count rate was ~38000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 09:19:32.7 UT, 74.6 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 304.4377, 5.2786 which is equivalent to: RA(J2000) = 20h 17m 45.05s Dec(J2000) = +05d 16' 43.0" with an uncertainty of 11.9 arcseconds (radius, 90% containment). This location is 145 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 0.1 s image was 1.25e-08 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 250 seconds with the U filter starting 297 seconds after the BAT trigger. An afterglow candidate has been found in the initial data products with a magnitude of u = 13.81 +/- 0.03. No correction has been made for the expected extinction corresponding to E(B-V) of 0.162. The preliminary UVOT position is RA=304.43748, Dec = 5.28337 (J2000), which is equivalent to: RA = 20h 17m 45.0s, Dec = +05d 17m 00.1s (J2000) with an uncertainty of about an arcsecond. Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 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/)
GCN 30678 table
GRB_name GRB210822A
GCN_number 30678
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 30678 SUBJECT: GRB 210822A: GECAM detection DATE: 21/08/22 11:31:19 GMT FROM: Shaolin Xiong at IHEP C. W. Wang, S. L. Xiong, X. Y. Zhao, X. Y. Song, C. Cai, C. Y. Li, Y. Huang, S. L. Xie, J. C. Liu, Y. Q. Zhang, Y. Zhao, Z. W. Guo, C. Zheng, Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He, B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang, J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma, G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song, G. X. Sun, X. L. Sun, Y. L. Tuo, J. Z. Wang,X. L. Zhang, W. C. Xue, X. Y. Wen, S. Xiao, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi, B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang, P. Wang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng, X. Zhou (IHEP), report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered in-flight by a long bright burst, GRB 210822A, at 2021-08-22T09:18:18.00 UTC (denoted as T0), which is also observed by Swift/BAT (GCN #30677). Its alert data was downlinked to the ground through the short message service of BeiDou Navigation Satellite System (BDS). According to the GECAM-B light curves in about 30-1000 keV from BDS alert data, this burst mainly consists of multiple pulses with a duration of about 15 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_83323099.png An automatic localization was calculated using the light curves and spectrum, and the GECAM location is consistent with the Swift/BAT 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).
GCN 30679 table
GRB_name GRB210822A
GCN_number 30679
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 30679 SUBJECT: GRB 210822A: KAIT Optical Afterglow Confirmation DATE: 21/08/22 15:25:27 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to the Swift GRB 210822A (Page et al., GCN 30677; see also GECAM detection, Wang et al., GCN 30678) starting at 09:20:02 UT, 104s after the burst. Observations were performed with a sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. The bright optical afterglow reported by UVOT (Page et al., GCN 30677) was clearly detected in our single image. We measure its brightness of 11.4 mag in our first clear image at 114s after the burst, then decayed to 16.1 mag at 2690s after the burst. A preliminary KAIT clear band light curve is available at: https://w.astro.berkeley.edu/~zwk/grb/GRB210822A/GRB210822A_kait.png
GCN 30680 table
GRB_name GRB210822A
GCN_number 30680
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 30680 SUBJECT: GRB 210822A: RATIR Optical Detections DATE: 21/08/22 16:59:44 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Eleonora Troja (GSFC), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), Rosa L. Becerra (UNAM), Simone Dichiara (UMD), and Océlotl López (UNAM) report: We observed the field of GRB 210822A (Page, et al., GCN 30677) with the Reionization and Transients Infrared Camera (RATIR) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2021/08 22.39 to 2021/08 22.41 UTC (1.2 minutes to 0.49 hours after the BAT trigger), obtaining a total of 0.19 hours exposure in the r and i bands. We detect the fading OT (see, Zheng & Filippenko, GCN 30679) with high confidence. The flux varies approximately as t^(-1) from i = 13.2 to i = 15.8 (and r=15.6). These preliminary magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.
GCN 30681 table
GRB_name GRB210822A
GCN_number 30681
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 30681 SUBJECT: Swift GRB 210822A: Global MASTER-Net observations report DATE: 21/08/22 17:07:28 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 210822A ( K. L. Page et al., GCN 30677) errorbox 27300 sec after notice time and 27365 sec after trigger time at 2021-08-22 16:54:24 UT, with upper limit up to 16.2 mag. Observations started at twilight. The observations began at zenith distance = 68 deg. The sun altitude is -8.8 deg. The galactic latitude b = -17 deg., longitude l = 48 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1697012 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 27456 | MASTER-SAAO | C | 180 | 16.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 30682 table
GRB_name GRB210822A
GCN_number 30682
Detection_method Swift-XRT Det
ra 304.4376°
decl 5.2835°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30682 SUBJECT: GRB 210822A: Enhanced Swift-XRT position DATE: 21/08/22 17:08:09 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 501 s of XRT Photon Counting mode data and 2 UVOT images for GRB 210822A, 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 = 304.43756, +5.28349 which is equivalent to: RA (J2000): 20h 17m 45.01s Dec (J2000): +05d 17' 00.6" with an uncertainty of 2.0 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.
GCN 30684 table
GRB_name GRB210822A
GCN_number 30684
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 30684 SUBJECT: GRB 210822A: Nanshan/NEXT optical observations DATE: 21/08/22 18:35:26 GMT FROM: Dong Xu at NAOC/CAS S.Y. Fu (NAOC), Z.P. Zhu (NAOC,HUST), X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 210822A (Page et al., GCN 30677) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 15x100 s frames in the Sloan r-band and 10x100 s frames in the V-band, starting at 14:42:53 UT on 2021-08-22, i.e., 5.41 hr after the BAT trigger. The optical afterglow (e.g., Page et al., GCN 30677; Zheng & Filippenko, GCN 30679) of the burst is clearly detected in our stacked images. Preliminary photometry results are as follows: Tmid (UT) Tmid-T0(day) Mag MagErr Filter 2021-08-22T14:58:04 0.236 18.53 0.06 r 2021-08-22T15:54:29 0.275 18.88 0.08 V calibrated with nearby PanSTARRS stars.
GCN 30687 table
GRB_name GRB210822A
GCN_number 30687
Detection_method Fermi LAT Det
t_trigger 9:18:18 UTC
ra 304.6000°
decl 4.9000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30687 SUBJECT: GRB 210822A: Fermi-LAT detection DATE: 21/08/22 20:02:07 GMT FROM: Masanori Ohno at Hiroshima U M. Ohno (Eotvos U./Hiroshima U.), D. Kocevski (NASA/MSFC), F. Longo (University and INFN, Trieste), a F. Dirirsa (LAPP, Annecy) report on behalf of the Fermi-LAT Collaboration: On August 22th, 2021, Fermi-LAT detected high-energy emission from GRB 210822A, which was also detected by Swift-BAT (trigger1069788; Page et al. GCN Circ. 30677) and GECAM (Wang et al., GCN Circ. 30678). The best LAT on-ground location is found to be RA, Dec 304.6, 4.9 (degrees, J2000) with an error radius of 0.5 deg (90% containment, statistical error only). This was 83 deg from the LAT boresight at the time of the Swift trigger: T0 = 09:18:18 UT. And the burst came into the LAT boresight about 500 s after the Swift trigger time. The data from the Fermi-LAT show a significant increase in the event rate after the Swift trigger that is spatially correlated with the Swift emission with high significance. The photon flux above 100 MeV in the time interval 500-10000 s after the Swift trigger is 2.5(-/+ 0.8) ph/cm2/s. The estimated photon index above 100 MeV is -2.4 (-/+ 0.3). The highest-energy photon is a 1.0 GeV event which is observed 855 seconds after the Swift trigger. The Fermi-LAT point of contact for this burst is Feraol F. Dirirsa (dirirsa@lapp.in2p3.fr ). 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 30689 table
GRB_name GRB210822A
GCN_number 30689
Detection_method Swift-BAT Det
ra 304.4610°
decl 5.2650°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30689 SUBJECT: GRB 210822A: Swift-BAT refined analysis DATE: 21/08/23 01:10:30 GMT FROM: Amy Lien at GSFC A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 210822A (trigger #1069788) (Page et al., GCN Circ. 30677). The BAT ground-calculated position is RA, Dec = 304.461, 5.265 deg which is RA(J2000) = 20h 17m 50.7s Dec(J2000) = +05d 15' 54.9" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 64%. The mask-weighted light curve shows a multi-peaked structure that starts and peaks at T0. The main pulse structure ends at ~T+20 s, followed by a long tail lasting till ~T+400 s. T90 (15-350 keV) is 180.8 +- 42.7 sec (estimated error including systematics). The time-averaged spectrum from T-0.37 to T+402.66 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.30 +- 0.04. The fluence in the 15-150 keV band is 2.0 +- 0.04 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+0.00 sec in the 15-150 keV band is 27.7 +- 0.7 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/1069788/BA/
GCN 30691 table
GRB_name GRB210822A
GCN_number 30691
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 30691 SUBJECT: GRB 210822A: Swift-XRT refined Analysis DATE: 21/08/23 08:08:50 GMT FROM: Phil Evans at U of Leicester M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and K.L. Page report on behalf of the Swift-XRT team: We have analysed 7.3 ks of XRT data for GRB 210822A (Page et al. GCN Circ. 30677), from 64 s to 58.6 ks after the BAT trigger. The data comprise 1.2 ks in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 30682). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.93 (+0.09, -0.06). At T+145 s the decay steepens to an alpha of 3.2 (+1.8, -0.8). The light curve breaks again at T+157 s to a decay with alpha=1.081 (+0.016, -0.015), again at T+3863 s s to alpha=1.81 (+0.12, -0.11), and again at T+22.4 ks s to alpha=-0.1 (+0.5, -1.4), before a final break at T+29.6 ks s after which the decay index is 1.7 (+/-0.3). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.829 (+/-0.019). The best-fitting absorption column is 1.89 (+/-0.07) x 10^21 cm^-2, in excess of the Galactic value of 1.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.77 (+/-0.12) and a best-fitting absorption column of 2.3 (+/-0.5) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.3 (+/-0.5) x 10^21 cm^-2 Galactic foreground: 1.5 x 10^21 cm^-2 Excess significance: 3.1 sigma Photon index: 1.77 (+/-0.12) If the light curve continues to decay with a power-law decay index of 1.7, the count rate at T+24 hours will be 0.050 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x 10^-12 (2.6 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01069788. This circular is an official product of the Swift-XRT team.
GCN 30692 table
GRB_name GRB210822A
GCN_number 30692
Detection_method Swift-BAT Det
redshift 1.7360
Circular_text TITLE: GCN CIRCULAR NUMBER: 30692 SUBJECT: GRB 210822A: NOT photometry and spectroscopy DATE: 21/08/23 08:25:52 GMT FROM: Dong Xu at NAOC/CAS Z.P. Zhu (NAOC, HUST), L. Izzo (DARK/NBI), S.Y.Fu, D. Xu (NAOC), J.P.U. Fynbo (DAWN/NBI), E. Paraskeva, S. Vitali (NOT), report on behalf of a larger collaboration: We observed the bright optical afterglow of GRB 210822A (Page et al., GCN 30677; Wang et al., GCN 30678; Ohno et al., GCN 30687) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 3x120s frames in the Sloan r-filter, starting at 23:11:50 UT on 2021-08-22 (i.e., ~ 13.89 hr after the BAT trigger). The previously reported optical afterglow (e.g., Page et al., GCN 30677; Zheng & Filippenko, GCN 30679; Butler et al., GCN 30680; Lipunov et al., GCN 30681; Fu et al., GCN 30684) has decayed to m(r) = 19.71 +/- 0.02, calibrated with the PS1 field. Subsequently 4x1200 s spectroscopy was carried out. A continuum is detected over the whole wavelength range of 3700-9500 AA, superimposed with some absorption features, among which prominent Fe II, Mg II, Mg I, and Al III lines were identified at a common redshift of z = 1.736. We conclude that this is the redshift of the burst.
GCN 30693 table
GRB_name GRB210822A
GCN_number 30693
Detection_method AstroSat CZTI
Circular_text TITLE: GCN CIRCULAR NUMBER: 30693 SUBJECT: GRB 210822A: AstroSat CZTI detection DATE: 21/08/23 09:13:47 GMT FROM: Gaurav Waratkar at IIT,Bombay V. Prasad (IUCAA), P. Sawant (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, 2020, arxiv:2011.07067) showed detection of a bright long GRB 210822A, which was also detected by Swift (Page et al., GCN 30677), GECAM (Wang et al., GCN 30678), and Fermi-LAT (Ohno et al., GCN 30687). The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2021-08-22 09:18:17.50 UT. The measured peak count rate associated with the burst is 2190 (+85, -91) cts/s above the background in the combined data of four quadrants, with a total of 12961 (+301, -314) cts. The local mean background count rate was 530 (+2, -3) cts/s. Using cumulative rates, we measure a T90 of 10 (+0.2, -0.2) s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2021-08-22 09:18:18.97 UT. The measured peak count rate is 3587 (+117, -127) cts/s above the background in the combined Veto data of four quadrants, with a total of 24196 (+541, -655) cts. The local mean background count rate was 1799 (+4, -4) cts/s. We measure a T90 of 12 (+0.5, -0.5) 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 [1]. 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. Links: ------ [1] http://astrosat.iucaa.in/czti/?q=grb
GCN 30694 table
GRB_name GRB210822A
GCN_number 30694
Detection_method Konus-Wind Det
t_trigger 9:18:22.974 UTC
redshift 1.7360
Circular_text TITLE: GCN CIRCULAR NUMBER: 30694 SUBJECT: Konus-Wind detection of GRB 210822A DATE: 21/08/23 12:38:10 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 210822A (Swift detection: Page et al., GCN 30677; GECAM detection: Wang et al., GCN 30678; Fermi-LAT detection: Ohno et al., GCN 30687; AstroSat CZTI detection: Ohno et al., GCN 30693) triggered Konus-Wind (KW) at T0=33502.974 s UT (09:18:22.974). The burst light curve shows a bright, multi-peaked pulse which starts at ~T0-1 s and has a total duration of ~12 s, followed by a weaker decaying emission visible up to ~T0+50 s. The emission in the main pulse is seen up to ~15 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB210822_T33502/ As observed by Konus-Wind, the burst had a fluence of (1.20 ± 0.11)x10^-4 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 0.320 s, of (3.25 ± 0.28)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+18.176 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.64 (-0.06,+0.07), the high energy photon index beta = -2.39 (-0.15,+0.12), the peak energy Ep = 398 (-29,+30) keV, chi2 = 124/96 dof. The spectrum near the peak count rate (measured from T0+4.096 to T0+7.936 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.59 (-0.15,+0.18), the high energy photon index beta = -2.08 (-0.18,+0.12), the peak energy Ep = 429 (-83,+108) keV, chi2 = 75/63 dof. Assuming the redshift z=1.736 (Zhu et al., GCN 30692) and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the isotropic energy release E_iso to (9.5 ± 0.8)x10^53 erg, the isotropic luminosity L_iso to (7.0 ± 0.6)x10^53 erg/s, the rest-frame peak energy of the time-integrated spectrum Epi,z to (1090 ± 80) keV, and the rest-frame peak energy of the 'peak' spectrum Epp,z to (1175 ± 250) keV. With these values, GRB 210822A lies within 68% prediction bands for both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2021, ApJ, 908, 83), see http://www.ioffe.ru/LEA/GRBs/GRB210702_T68826/GRB210822A_rest_frame.pdf All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.
GCN 30696 table
GRB_name GRB210822A
GCN_number 30696
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 30696 SUBJECT: GRB 210822A: GECAM refined analysis DATE: 21/08/23 15:00:34 GMT FROM: Chenwei Wang at IHEP C. W. Wang, S. L. Xiong, X. Y. Zhao, X. Y. Song, C. Cai, C. Y. Li, Y. Huang, S. L. Xie, J. C. Liu, Y. Q. Zhang, Y. Zhao, Z. W. Guo, C. Zheng, Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He, B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang, J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma, G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song, G. X. Sun, X. L. Sun, Y. L. Tuo, J. Z. Wang,X. L. Zhang, W. C. Xue, X. Y. Wen, S. Xiao, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi, B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang, P. Wang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng, X. Zhou (IHEP), report on behalf of GECAM team: At 2021-08-22T09:18:18.00 UTC(denoted as T0), GECAM-B was triggered in-flight by a long bright burst, GRB 210822A, which is also observed by Swift/BAT (GCN #30677). The spectrum was calculated using the GECAM-B trigger data. The time-integrated spectrum (measured from T0 to T0+15) is best fit in the 20 keV - 5 MeV range by a power law with high energy exponential rolloff model: dN/dE ~ (E^alpha)*exp(-E/beta) with alpha = -0.8595 +/- 0.029, and beta = 394.9867 +/- 23.466 keV. The event fluence (10-1000 keV) in this time interval is (7.54 +0.10/-0.19)E-05 erg/cm^2. 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).
GCN 30697 table
GRB_name GRB210822A
GCN_number 30697
Detection_method Fermi LAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 30697 SUBJECT: GRB 210822A: Detection by GRBAlpha DATE: 21/08/23 15:42:18 GMT FROM: Masanori Ohno at Hiroshima U M. Ohno (Eotvos U./Konkoly Observatory/Hiroshima U.), J. Ripa (Masaryk U.), H. Takahashi (Hiroshima U.), A. Pal, L. Meszaros, B. Csak (Konkoly Observatory), N. Werner, M. Topinka, F. Munz, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Yuusuke Uchida, Helen Poon, H. Matake, N. Uchida (Hiroshima U.), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.) -- the GRBAlpha collaboration. The long duration GRB 210822A (Swift-BAT detection; Page et al. GCN Circ. 30677, GECAM detection; Wang et al. GCN Circ. 30678, Fermi-LAT detection; Ohno et al. GCN Circ. 30687) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The light curve shows a strong spike structure with a high significance of a SNR ~ 45. The observed total duration was about 12 sec. GRBAlpha was leaving the outer Van Allen radiation belt and thus GRB 210822A is superimposed on a high background due to trapped electrons. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB210822A_GCN.pdf GRBAlpha is a demonstration mission for a future CubeSats constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. GRBAlpha was launched on 2021 March 22 from Baikonur. After its commissioning phase, the scientific observations are now under way. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN 30701 table
GRB_name GRB210822A
GCN_number 30701
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 30701 SUBJECT: GRB 210822A: Abbey Ridge Observatory optical afterglow observation DATE: 21/08/24 06:49:06 GMT FROM: Filipp Dmitrievich Romanov at Amateur astronomer Filipp D. Romanov (Russia) and David J. Lane (Saint Mary's University, Canada) report: Filipp Romanov observed optical afterglow of GRB 210822A (Page et al., GCN Circ. 30677) remotely using 0.355-m f/6.2 Schmidt-Cassegrain telescope of Abbey Ridge Observatory (it is owned by Dave Lane) in Canada, on 2021-08-23. Four images (with exposures: 720, 720, 600 and 720 seconds) were obtained with Cousins R filter from 00:54:39 to 02:17:30 UTC. Faint (SNR = 5) optical afterglow (with UVOT position) is visible in the stacked image (mid time = 01:36:04 UTC, that is 16.296 hours after the trigger). Romanov measured its magnitude comparing to transformed (using formula Rc=r’-0.22 from Dymock & Miles, 2009) r' magnitudes of nearby stars from Pan-STARRS DR1 catalogue (Chambers et al., 2016). The measured magnitude = 20.1 +/- 0.3. Magnitude was not corrected for Galactic extinction. Stacked image available here: http://abbeyridgeobservatory.ca/images/grb210822a.jpg
GCN 30703 table
GRB_name GRB210822A
GCN_number 30703
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 30703 SUBJECT: GRB 210822A: GROND observations DATE: 21/08/24 15:19:39 GMT FROM: Ana Nicuesa at TLS Tautenburg A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg) and A. Rau (MPE Garching) report: We observed the field of GRB 210822A (Swift trigger #1069788; Page et al., GCN 30677) with GROND mounted at the 2.2m MPG telescope at La Silla Observatory (Chile). Observations started at 02:54 UT on August 23, about 17.6 hr after the GRB trigger. They were performed at an average seeing of 2.2 arcsec and at an average airmass of 1.2. Based on combined images with 10 min total exposure, at a mid-time of 03:02 UT on 2021-08-23 for the afterglow (Page et al., GCN 30677; Zheng & Filippenko, GCN 30679; Butler et al., GCN 30680; Fu et al., GCN 30684; Zhu et al., GCN 30692; Romanov & Lane, GCN 30701) we derive the following AB magnitudes: g' = 20.37 +/- 0.09, r' = 20.10 +/- 0.05, i' = 19.92 +/- 0.05. Given magnitudes are calibrated against Pan-STARRS and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E(B-V) = 0.14 mag in the direction of the burst (Schlegel et al. 1998). We thank Angela Hempel for excellent support and for performing the observations.
GCN 30710 table
GRB_name GRB210822A
GCN_number 30710
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 30710 SUBJECT: GRB 210822A: Swift/UVOT Detection DATE: 21/08/25 06:21:36 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 210822A 85 s after the BAT trigger (Page et al., GCN Circ. 30677). A fading source consistent with the XRT position (Page et al. GCN Circ. 30677) and the previously reported UVOT source is is detected in the initial UVOT exposures. 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 (fc) 86 236 147 13.63+/-1.10 white 577 1200 205 15.35+/-0.02 white 4965 5058 91 17.43+/-0.05 white 34405 35230 804 19.15+/-0.05 white 149533 190336 1894 20.64+/-0.11 v 627 1250 77 15.07+/-0.05 v 27494 28215 702 18.68+/-0.13 b 553 1176 58 15.31+/-0.04 b 4760 4960 196 17.56+/-0.06 b 33493 34400 885 19.18+/-0.08 u (fc) 298 548 245 13.78+/-0.03 u 700 1304 39 14.86+/-0.05 u 4555 4755 196 16.85+/-0.05 u 57947 58635 670 19.73+/-0.19 uvw1 676 1299 77 15.28+/-0.07 uvw1 39434 96567 1775 19.90+/-0.22 uvm2 824 1274 38 >17.66 uvm2 92215 93015 788 >20.06 uvw2 602 1225 77 17.21+/-0.18 uvw2 21659 64335 1469 20.40+/-0.34 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.162 in the direction of the burst (Schlegel et al. 1998).
GCN 30712 table
GRB_name GRB210822A
GCN_number 30712
Detection_method Optical
redshift 1.7360
Circular_text TITLE: GCN CIRCULAR NUMBER: 30712 SUBJECT: GRB 210822A: TSHAO optical observation DATE: 21/08/25 09:49:39 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Kusakin (FAP), I. Reva (FAP), Pozanenko (IKI), N. Pankov (HSE), V. Kim (FAP) report on behalf of GRB-IKI-FuN: We observed GRB 210822A (Page et al., GCN 30677; Wang et al., GCN 30678; Prasad et al., GCN 30693; Frederiks et al., GCN 30694) with Zeiss-1000 telescope of Tien Shan Astronomical Observatory on Aug. 22 (UT) 15:48:55 -- 18:48:47. We obtained series with 20 and 30 sec exposition in R-filter. The optical afterglow (Page et al., GCN 30677; Zheng et al., GCN 30679; Butler et al., GCN 30680; Fu et al., GCN 30684; Zhu et al., GCN 30692; Romanov et al., GCN 30701; Guelbenzu et al., GCN 30703; Siegel et al., GCN 30710) at redshift z = 1.736 (Zhu et al., GCN 30692) is detected in stacked images. Preliminary photometry of the afterglow in a stacked image of the second series is following. Date UT start t-T0 Filter Exp. OT Err. UL(3 sigma) (mid, days) (s) 2021-08-22 17:26:41 0.36184 R 196*20 18.63 0.03 21.0 The photometry is based on nearby USNO-B1.0 stars. USNO-B1.0 RA Dec R2 20:18:06.64416 +05:17:24.1404 12.33 20:17:59.55288 +05:18:19.5912 13.05
GCN 30713 table
GRB_name GRB210822A
GCN_number 30713
Detection_method VLA Det
ra 304.4375°
decl 5.2832°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30713 SUBJECT: GRB 210822A: VLA detection DATE: 21/08/25 14:47:06 GMT FROM: Tanmoy Laskar at U of Bath T. Laskar (University of Bath), K. D. Alexander (Northwestern), E. Berger (Harvard), R. Chornock (UC Berkeley), W. Fong (Northwestern), R. Margutti (UC Berkeley), C. G. Mundell (University of Bath), P. Schady (University of Bath), and G. Schroeder (Northwestern) report on behalf of a larger collaboration: "We observed GRB 210822A (Page et al. GCN 30677) with the Karl G. Jansky Very Large Array (VLA) beginning on 2021 August 24 at 05:30 UT (1.9 d after the burst). At a mean frequency of 14.8 GHz, we detect a radio source with a preliminary flux density of ~ 0.4 mJy at the position: RA (J2000) = 20:17:44.992 +/- 0.001 Dec (J2000) = 05:16:59.53 +/- 0.02 consistent with the position of the optical afterglow (Page et al., GCN 30677) and the Swift/XRT afterglow (Evans al., GCN 30682). Follow-up observations are planned. We thank the VLA staff for rapidly executing these observations."
GCN 30714 table
GRB_name GRB210822A
GCN_number 30714
Detection_method Optical
redshift 1.7360
Circular_text TITLE: GCN CIRCULAR NUMBER: 30714 SUBJECT: GRB 210822A: TSHAO continued optical observation DATE: 21/08/25 16:34:52 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Kusakin (FAP), I. Reva (FAP), Pozanenko (IKI), N. Pankov (HSE), V. Kim (FAP) report on behalf of GRB-IKI-FuN: We continue observations of GRB 210822A (Page et al., GCN 30677; Wang et al., GCN 30678; Prasad et al., GCN 30693; Frederiks et al., GCN 30694) with Zeiss-1000 telescope of Tien Shan Astronomical Observatory. on Aug. 22 (UT) 15:48:55 -- 18:48:47. We obtained series in R-filter starting on 2021-08-24 (UT) 16:47:35. The optical afterglow (Page et al., GCN 30677; Zheng et al., GCN 30679; Butler et al., GCN 30680; Fu et al., GCN 30684; Zhu et al., GCN 30692; Romanov et al., GCN 30701; Guelbenzu et al., GCN 30703; Siegel et al., GCN 30710; Belkin et al., GCN 30712) at the redshift of z = 1.736 (Zhu et al., GCN 30692) is detected in stacked image. Preliminary photometry of the afterglow in a stacked image is following. Date UT start t-T0 Filter Exp. OT Err. UL(3 sigma) (mid, days) (s) 2021-08-24 16:47:35 2.33041 R 3180 21.60 0.26 22.0 The photometry is based on nearby USNO-B1.0 stars. USNO-B1.0 RA Dec R2 20:18:06.64416 +05:17:24.1404 12.33 20:17:59.55288 +05:18:19.5912 13.05
GCN 30723 table
GRB_name GRB210822A
GCN_number 30723
Detection_method Fermi LAT Det
redshift 1.7360
Circular_text TITLE: GCN CIRCULAR NUMBER: 30723 SUBJECT: GRB 210822A: CAHA 2.2m observations DATE: 21/08/27 00:27:10 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), A. Fernandez, I. Hermelo, and P. Martin (all CAHA) report: We observed the bright GRB 210822A (Swift detection: Page et al., GCN #30677; GECAM detection: Wang et al., GCN #30678; Fermi-LAT detection: Ohno et al., GCN #30687; AstroSat CZTI detection: Prasad et al., GCN #30693; Konus-Wind detection: Frederiks et al., GCN #30694; GRBAlpha detection: Ohno et al., GCN #30697) at a redshift of z = 1.736 (Zhu et al., GCN #30692) with CAFOS mounted on the 2.2m CAHA telescope at Calar Alto, Alemria, Spain. The first epoch was obtained under very inclement conditions (almost overcast), and one 60 s as well as four 90 s images were useful. The second epoch, two nights later, was obtained under significantly improved (but still not really good) conditions, and 31 x 30 s images were obtained. The optical afterglow (Page et al., GCN #30677; Zheng et al., GCN #30679; Butler et al., GCN #30680; Fu et al., GCN #30684; Zhu et al., GCN #30692; Romanov & Lane, GCN #30701; Nicuesa Guelbenzu et al., GCN #30703; Siegel et al., GCN #30710; Belkin et al., GCN #30712; Belkin et al., GCN #30714) is faintly detected in the first epoch, but not detected in the second epoch. Against three nearby Pan-STARRS comparison stars, we measure (AB magnitudes): i' = 18.56 +/- 0.14 mag at 0.43283 days after the GRB, and i' > 21.5 mag at 2.5206 mag after the GRB.
GCN 30744 table
GRB_name GRB210822A
GCN_number 30744
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 30744 SUBJECT: GRB 210822A: CALET Gamma-Ray Burst Monitor detection DATE: 21/08/30 07:06:23 GMT FROM: Valentin Pal'shin at AGU K. Kobayashi (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 210822A (Swift detection: Page et al., GCN Circ. 30677, Lien et al., GCN Circ. 30689; GECAM detection: Wang et al., GCN Circ. 30678, 30696; Fermi-LAT detection: Ohno et al., GCN Circ. 30687; AstroSat CZTI detection: Prasad et al., GCN Circ. 30693; Konus-Wind detection: Frederiks et al., GCN Circ. 30694; GRBAlpha detection: Ohno et al., GCN Circ. 30697; https://gcn.gsfc.nasa.gov/other/210822A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:18:18.162 UTC on 22 August 2021. The burst signal was seen by all CGBM detectors. Because of a problem in one of the ground alert processing script, the GCN notice was not distributed automatically for this event. The burst light curve shows a multi-peaked structure which starts at T-0.2 sec, peaks at T+0.1 sec and ends at T+11.0 sec. The T90 and T50 durations measured by the SGM data are 10.1 +- 0.5 sec and 5.8 +- 0.4 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1313658800/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.