GRB201021C

This page lists all entries on GRB201021C in GRBweb

Summary Fermi GBM IPN Swift GCN 28730 GCN 28733 GCN 28736 GCN 28739 GCN 28745 GCN 28748 GCN 28754 GCN 28755 GCN 31752

Summary table
Variable Value Source
GRB_name_Fermi GRB201021852
T0 20:27:16.035 UTC Fermi_GBM
ra 12.5289° Swift
decl -55.8658° Swift
pos_error 5.44e-05° Swift
T90 35.328 s Fermi_GBM
T90_error 2.202 s Fermi_GBM
T90_start 20:27:16.035 UTC Fermi_GBM
fluence 1.68e-06 erg/cm² Fermi_GBM
fluence_error 4.27e-08 erg/cm² Fermi_GBM
redshift 1.0700
T100 35.328 s
GBM_located False
mjd 59143.85226892361 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB201021852
trigger_name bn201021852
ra 12.5500°
decl -55.3900°
datum 2020-10-21
t_trigger 20:27:21.923 UTC
T90 35.328 s
T90_error 2.202 s
T90_start 20:27:16.035 UTC
fluence 1.68e-06 erg/cm²
fluence_error 4.27e-08 erg/cm²
flux_1024 1.82e+00 erg/cm²/s
flux_1024_error 2.04e-01 erg/cm²/s
flux_1024_time -1.86e+00 erg/cm²/s
flux_64 3.70e+00 erg/cm²/s
flux_64_error 9.13e-01 erg/cm²/s
IPN table
GRB_name GRB201021C
ra 12.5500°
decl -55.8333°
pos_error 5.00e-02°
redshift 1.0700
Swift table
GRB_name GRB201021C
t_trigger 20:27:18 UTC
ra 12.5289°
decl -55.8658°
pos_error 5.44e-05°
T90 24.38 s
fluence 1.00e-06 erg/cm²
redshift 1.0700
GCN 28730 table
GRB_name GRB201021C
GCN_number 28730
Detection_method Swift Det
t_trigger 20:27:18 UTC
ra 12.5500°
decl -55.8390°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28730 SUBJECT: GRB 201021C: Swift detection of a burst with an optical counterpart DATE: 20/10/21 20:40:16 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), M. G. Bernardini (INAF-OAB), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF), S. Laha (GSFC/UMBC/CRESST), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), M. J. Moss (GWU), T. Sakamoto (AGU), T. Sbarrato (INAF-OAB) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 20:27:18 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201021C (trigger=1001130). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 12.550, -55.839 which is RA(J2000) = 00h 50m 12s Dec(J2000) = -55d 50' 20" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 25 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 20:29:00.6 UT, 102.0 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 12.53057, -55.86729 which is equivalent to: RA(J2000) = 00h 50m 07.34s Dec(J2000) = -55d 52' 02.2" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 109 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.05 x 10^20 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 105 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at RA(J2000) = 00:50:06.85 = 12.52855 DEC(J2000) = -55:51:56.7 = -55.86576 with a 90%-confidence error radius of about 1.10 arc sec. This position is 2.8 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.19. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is A. Y. Lien (amy.y.lien 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/)
GCN 28733 table
GRB_name GRB201021C
GCN_number 28733
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28733 SUBJECT: GRB 201021C: MASTER optical synchronously observation DATE: 20/10/21 21:46:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, A.Kuznetsov,K.Zhirkov, F.Balakin, V.Vladimirov, 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, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-SAAO started GRB 201021C (Lien et al. GCN 28730) observation by MASTER-II (2x4sq.deg.) in 2020-10-21 20:31:04UT and also detected OT at Swift-UVOT position (Lien et al. GCN 28730) in 2 polarization filters. MASTER very wide field cameras (Lipunov et al. 2010, Advances in Astronomy, vol.2010, 30L) observed this GRB _synchronously_ . Observation and reduction will continue.
GCN 28736 table
GRB_name GRB201021C
GCN_number 28736
Detection_method Swift-XRT Det
ra 12.5289°
decl -55.8655°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28736 SUBJECT: GRB 201021C: Enhanced Swift-XRT position DATE: 20/10/22 01:22:09 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 742 s of XRT Photon Counting mode data and 2 UVOT images for GRB 201021C, 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 = 12.52888, -55.86549 which is equivalent to: RA (J2000): 00h 50m 6.93s Dec (J2000): -55d 51' 55.8" with an uncertainty of 1.7 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 28739 table
GRB_name GRB201021C
GCN_number 28739
Detection_method Optical
redshift 1.0700
Circular_text TITLE: GCN CIRCULAR NUMBER: 28739 SUBJECT: GRB 201021C: VLT/X-shooter redshift DATE: 20/10/22 08:45:59 GMT FROM: Paolo D'Avanzo at INAF-OAB J.-B. Vielfaure (GEPI - Paris Observatory), D. Xu (NAO/CAS), J. Palmerio (GEPI - Paris Observatory), P. D'Avanzo (INAF-OAB), D. B. Malesani (DTU Space), J. P. U. Fynbo (DAWN/NBI), V. D'Elia (ASI/SSDC), D. A. Kann (HETH/IAA-CSIC) and N. R. Tanvir (Univ. Leicester) report on behalf of the Stargate collaboration: We observed the optical afterglow of GRB 201021C (Lien et al., GCN 28730; Lipunov et al., GCN 28733) using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. Our spectra cover the wavelength range 3000-21000 AA, and consist of 4 exposures by 600 s each. The observation started at 03:29:00 UT on 2020 Oct 22 (7.02 hr after the GRB). In a 30 s image taken with the acquisition camera on Oct 22.14 UT, we detect the optical afterglow, for which we measure a magnitude r = 19.97 +/- 0.02 (AB, calibrated against nearby stars from the SkyMapper catalog; Wolf et al. 2018, PASA, 35, 010). We clearly detect continuum over the whole X-shooter spectrum. From detection of multiple absorption features, which we interpret as due to Si II, Al II, Al III, Fe II and Mg II, we infer a redshift z = 1.070. In particular, weak fine structure lines from Fe II* are visible, which confirm the association of the absorption system with the GRB. We also detect Mg II and Mg I absorption features from an intervening system at z = 0.805. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Bin Yang and Fernando Selman.
GCN 28745 table
GRB_name GRB201021C
GCN_number 28745
Detection_method Swift-UVOT Det
ra 12.5289°
decl -55.8658°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28745 SUBJECT: GRB 201021C: Swift/UVOT Detection DATE: 20/10/22 13:16:47 GMT FROM: Samantha Oates at MSSL S. R. Oates (U.Birmingham) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 201021C 105 s after the BAT trigger (Lien et al., GCN Circ. 28730). A source consistent with the XRT position (Beardmore et al. GCN Circ. 28736) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 00:50:06.93 = 12.52886 (deg.) Dec (J2000) = -55:51:56.8 = -55.86577 (deg.) with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence). Preliminary detections 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) 105 255 147 16.66 +/- 0.03 white 598 617 19 16.22 +/- 0.05 v 647 667 19 16.49 +/- 0.16 b 573 593 20 16.80 +/- 0.10 u (FC) 317 567 246 15.76 +/- 0.03 u 722 742 19 16.06 +/- 0.10 uvm2 672 692 19 16.43 +/- 0.24 uvw2 623 643 19 16.68 +/- 0.22 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN 28748 table
GRB_name GRB201021C
GCN_number 28748
Detection_method Fermi GBM Det
t_trigger 20:27:21.920 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 28748 SUBJECT: GRB 201021C: Fermi GBM detection DATE: 20/10/22 15:41:24 GMT FROM: Stephen Lesage at Fermi-GBM Team S. Lesage (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 20:27:21.92 UT on 21 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201021C (trigger 625004846 / 201021852) which was also detected by the Swift/BAT (A. Y. Lien et al. 2020, GCN 28730). The Fermi GBM on-ground localization is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is ~59 degrees. The GBM light curve shows a single bright peak with a duration (T90) of about 35.3 s (50-300 keV). The time-averaged spectrum from T0-5.9 s to T0+29.4 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.1 +/- 0.2 and the cutoff energy, parameterized as Epeak, is 131.1 +/- 28.2 keV. The event fluence (10-1000 keV) in this time interval is (1.7 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0-1.9 s in the 10-1000 keV band is 1.82 +/- 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/"
GCN 28754 table
GRB_name GRB201021C
GCN_number 28754
Detection_method Swift-XRT Other
redshift 1.0700
Circular_text TITLE: GCN CIRCULAR NUMBER: 28754 SUBJECT: GRB 201021C: Swift-XRT refined Analysis DATE: 20/10/22 20:40:03 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , J. D. Gropp (PSU), J.A. Kennea (PSU) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 4.3 ks of XRT data for GRB 201021C (Lien et al. GCN Circ. 28730), from 105 s to 58.8 ks after the BAT trigger. The data comprise 62 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 28736). The light curve can be modelled with a power-law decay with a decay index of alpha=1.22 (+0.07, -0.06). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.62 (+0.19, -0.16). The best-fitting absorption column is 5 (+21, -5) x 10^20 cm^-2, at a redshift of 1.07, in addition to the Galactic value of 2.0 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 2.0 x 10^20 cm^-2 Intrinsic column: 5 (+21, -5) x 10^20 cm^-2 at z=1.07 Photon index: 1.62 (+0.19, -0.16) If the light curve continues to decay with a power-law decay index of 1.22, the count rate at T+24 hours will be 2.7 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x 10^-13 (1.1 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01001130. This circular is an official product of the Swift-XRT team.
GCN 28755 table
GRB_name GRB201021C
GCN_number 28755
Detection_method Swift-BAT Det
ra 12.5030°
decl -55.8620°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28755 SUBJECT: GRB 201021C: Swift-BAT refined analysis DATE: 20/10/22 22:30:34 GMT FROM: Hans Krimm at NSF/NASA-GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201021C (trigger #1001130) (Lien, et al., GCN Circ. 28730). The BAT ground-calculated position is RA, Dec = 12.503, -55.862 deg which is RA(J2000) = 00h 50m 00.6s Dec(J2000) = -55d 51' 44.0" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 80%. The mask-weighted light curve shows a single peak running from ~T-5 sec to T+20 sec, with a broad peak around T+3 sec. T90 (15-350 keV) is 24.38 +- 6.76 sec (estimated error including systematics). The time-averaged spectrum from T-4.19 to T+27.95 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.63 +- 0.15. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-3.62 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/1001130/BA/
GCN 31752 table
GRB_name GRB201021C
GCN_number 31752
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 31752 SUBJECT: GRB 201021C: TAROT Reunion observatory optical light curve DATE: 22/03/13 22:08:20 GMT FROM: Alain Klotz at IRAP-CNRS-OMP A. Klotz (CNRS-OMP-IRAP), M. Fortune, R. Augerai (Universite de la Renuion), P. Thierry (AGORA), L. Eymar, S. Antier, M. Boer, A. de Ugarte Postigo (CNRS-OCA-ARTEMIS), We analyzed archive images of the SWIFT trigger 1001130 (GRB 201021C, BAT detection by Lien et al. GCN Circ. 28730, early optical ground observations by Lipunov et al. GCN Circ. 28733, redshift by Vielfaure et al. GCN Circ. 28739) with the TAROT robotic telescope (D=18cm) located at Les Makes Observatory, Reunion Island, France. Images were acquired without any filter, camera FLI PL16803 and Takahashi Epsilon 180ED. According the reference star NOMAD-1 0340-0006028 R=13.85 we give the photometry of the GRB optical transient: t1(s) t2(s) R dmag 813 993 15.92 0.04 1003 1183 16.02 0.03 1190 1370 16.24 0.05 1388 1568 16.28 0.04 1575 1755 16.52 0.06 1762 1942 16.62 0.06 2048 2228 16.80 0.08 2236 2416 16.92 0.09 2425 3178 17.12 0.06 3198 4132 17.54 0.09 4139 9462 17.82 0.10 t1 and t2 are start and stop acquisition since the trigger. Magnitudes are not corrected for Galactic dust extinction.