GRB201020A

This page lists all entries on GRB201020A in GRBweb

Summary Fermi GBM IPN Swift GCN 28696 GCN 28697 GCN 28698 GCN 28700 GCN 28701 GCN 28703 GCN 28705 GCN 28706 GCN 28707 GCN 28708 GCN 28711 GCN 28713 GCN 28717 GCN 28737 GCN 28742 GCN 28744 GCN 28747 GCN 28789

Summary table
Variable Value Source
GRB_name_Fermi GRB201020241
T0 5:47:26 UTC GCN_circulars,Swift Det
ra 261.2278° Swift
decl 31.4284° Swift
pos_error 5.70e-05° Swift
T90 21.504 s Fermi_GBM
T90_error 3.114 s Fermi_GBM
T90_start 5:47:30.330 UTC Fermi_GBM
fluence 1.56e-06 erg/cm² Fermi_GBM
fluence_error 2.45e-08 erg/cm² Fermi_GBM
redshift 2.9030 GCN_circulars,Other
T100 25.834 s
GBM_located False
mjd 59142.241273148145 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB201020241
trigger_name bn201020241
ra 261.2279°
decl 31.4289°
datum 2020-10-20
t_trigger 5:47:45.178 UTC
T90 21.504 s
T90_error 3.114 s
T90_start 5:47:30.330 UTC
fluence 1.56e-06 erg/cm²
fluence_error 2.45e-08 erg/cm²
flux_1024 3.48e+00 erg/cm²/s
flux_1024_error 1.44e-01 erg/cm²/s
flux_1024_time -3.58e+00 erg/cm²/s
flux_64 5.41e+00 erg/cm²/s
flux_64_error 9.44e-01 erg/cm²/s
IPN table
GRB_name GRB201020A
ra 261.2458°
decl 31.4167°
pos_error 5.00e-02°
redshift 2.9030
Swift table
GRB_name GRB201020A
t_trigger 5:47:26 UTC
ra 261.2278°
decl 31.4284°
pos_error 5.70e-05°
T90 14.17 s
fluence 9.20e-07 erg/cm²
redshift 2.9030
GCN 28696 table
GRB_name GRB201020A
GCN_number 28696
Detection_method Swift Det
t_trigger 5:47:26 UTC
ra 261.2460°
decl 31.4250°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28696 SUBJECT: GRB 201020A: Swift detection of a burst with an optical counterpart. DATE: 20/10/20 05:59:53 GMT FROM: Kim Page at U.of Leicester E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC), N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), T. Sakamoto (AGU), B. Sbarufatti (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 05:47:26 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201020A (trigger=1000926). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 261.246, +31.425 which is RA(J2000) = 17h 24m 59s Dec(J2000) = +31d 25' 30" 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 20 sec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~17 sec after the trigger. The XRT began observing the field at 05:49:47.6 UT, 141.5 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 261.2279, 31.4288 which is equivalent to: RA(J2000) = 17h 24m 54.71s Dec(J2000) = +31d 25' 43.8" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 57 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 3.70 x 10^20 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 144 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 17:24:54.67 = 261.22779 DEC(J2000) = +31:25:42.0 = 31.42834 with a 90%-confidence error radius of about 0.62 arc sec. This position is 5.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.14 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.04. Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.it). 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 28697 table
GRB_name GRB201020A
GCN_number 28697
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 28697 SUBJECT: GRB 201020A: MITSuME Akeno optical observation DATE: 20/10/20 10:25:22 GMT FROM: Adachi Ryo at Tokyo Institute of Tech R. Adachi, R. Hosokawa, K. L. Murata, M. Niwano, F. Ogawa, N. Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration: We observed the field of GRB 201020A (E. Ambrosi et al.,GCN Circular #28696) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started at 2020-10-20 08:31:00 UT. The first 28 images were heavily affected by twilight at Akeno Observatory. We detected the point source at the position consistent with the afterglow detected previously (E. Ambrosi et al. GCN #28696). We measured the magnitudes as follows. T0+[min] MID-UT T-EXP[sec] measured magnitudes ------------------------------------------------------------------------------------------------ 196 09:15:39 1260 g'=19.4+/-0.2, Rc=18.4+/-0.1, Ic=18.4+/-0.2 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 and PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al., accepted for publication in PASJ, https://arxiv.org/abs/2008.11486; https://github.com/MNiwano/Eclaire).
GCN 28698 table
GRB_name GRB201020A
GCN_number 28698
Detection_method Swift-XRT Det
ra 261.2283°
decl 31.4280°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28698 SUBJECT: GRB 201020A: Enhanced Swift-XRT position DATE: 20/10/20 13:05:56 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 729 s of XRT Photon Counting mode data and 1 UVOT images for GRB 201020A, 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 = 261.22827, +31.42804 which is equivalent to: RA (J2000): 17h 24m 54.78s Dec (J2000): +31d 25' 40.9" with an uncertainty of 1.8 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 28700 table
GRB_name GRB201020A
GCN_number 28700
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28700 SUBJECT: Swift GRB 201020A: Global MASTER-Net observations report DATE: 20/10/20 16:00:40 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 201020A ( E. Ambrosi et al., GCN 28696) errorbox 35426 sec after notice time and 35521 sec after trigger time at 2020-10-20 15:39:27 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenith distance = 32 deg. The sun altitude is -9.4 deg. The galactic latitude b = 31 deg., longitude l = 55 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1464820 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 35612 | MASTER-Tavrida | C | 180 | 16.4 | 36013 | MASTER-Tavrida | C | 180 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 28701 table
GRB_name GRB201020A
GCN_number 28701
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28701 SUBJECT: GRB 201020A: Nanshan/NEXT optical observations DATE: 20/10/20 16:08:23 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 201020A (Ambrosi et al., GCN 28696) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 15x120s frames in the Sloan r-band, starting at 13:48:25 UT on 2020-10-20, i.e., 8.02 hr after the BAT trigger. The optical afterglow (Ambrosi et al., GCN 28696; Adachi et al., GCN 28697) of the burst is clearly detected in our stacked image, with r = 19.69 +/- 0.06 mag at T_mid = 0.3461 day post-burst, calibrated with nearby PS1 stars.
GCN 28703 table
GRB_name GRB201020A
GCN_number 28703
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28703 SUBJECT: GRB 201020A: Assy optical observations DATE: 20/10/20 17:50:28 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), V. Kim (AFIF, Pulkovo Observatory), M. Krugov (AFIF), N. Pankov (HSE), A. Volnova (IKI) report on behalf of IKI GRB FuN: We observed the filed of GRB 201020A (Ambrosi et al., GCN 28696) with AZT-20 telescope of Assy-Turgen observatory starting on (UT) Oct. 20 (Ut) 14:00:44 (UT) in r'-filter. We clearly detect optical afterglow (Ambrosi et al., GCN 28696; Adachi et al., GCN 28697; Fu et al., GCN 28701). Preliminary photometry of the afterglow is following Date UT start t-T0 Filter Exp. OT Err. UL (3sigma) (mid, days) (s) 2020-10-20 14:00:44 0.36688 r'(AB) 70*60 19.70 0.03 23.8 The photometry is based on the nearby stars of PanSTARRS-PS1 catalog. SDSS-DR12_id r J172452.73+312623.9 18.459 J172455.96+312344.8 18.057 J172452.57+312302.1 17.618 J172456.76+312315.5 16.876
GCN 28705 table
GRB_name GRB201020A
GCN_number 28705
Detection_method Swift-BAT Det
ra 261.2390°
decl 31.4280°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28705 SUBJECT: GRB 201020A: Swift-BAT refined analysis DATE: 20/10/20 20:08:10 GMT FROM: Hans Krimm at NSF/NASA-GSFC T. Sakamoto (AGU), E. Ambrosi (INAF-IASFPA), 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), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201020A (trigger #1000926) (Ambrosi et al., GCN Circ.28696). The BAT ground-calculated position is RA, Dec = 261.239, 31.428 deg which is RA(J2000) = 17h 24m 57.4s Dec(J2000) = +31d 25' 41.8" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 90%. The mask-weighted light curve shows a single symmetrical peak starting at ~T+8 sec, peaking at T+17 sec, and decaying to background by T+26 sec. T90 (15-350 keV) is 14.17 +- 4.68 sec (estimated error including systematics). The time-averaged spectrum from T+8.23 to T+30.17 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.25 +- 0.14. The fluence in the 15-150 keV band is 9.2 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+17.17 sec in the 15-150 keV band is 2.1 +- 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/1000926/BA/
GCN 28706 table
GRB_name GRB201020A
GCN_number 28706
Detection_method Fermi GBM Det
t_trigger 5:47:45.180 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 28706 SUBJECT: GRB 201020A: Fermi GBM observation DATE: 20/10/20 21:02:13 GMT FROM: Christian Malacaria at NASA-MSFC/USRA E. Bissaldi (Politecnico and INFN Bari), C. Malacaria (NASA-MSFC/USRA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 05:47:45.18 UT on 20 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201020A (trigger 624865670 / 201020241), which was also detected by the Swift/BAT (Ambrosi et al. 2020, GCN 28696). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 66 degrees. The GBM light curve shows a single emission episode with a duration (T90) of about 22 s (50-300 keV). The time-averaged spectrum from T0-10.2s to T0+10.2 s is best fit by a simple power law function with index -1.83 +/- 0.04. The event fluence (10-1000 keV) in this time interval is (2.47 +/- 0.17)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-3.6 s in the 10-1000 keV band is 3.48 +/- 0.14 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 28707 table
GRB_name GRB201020A
GCN_number 28707
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28707 SUBJECT: GRB 201020A: Swift-XRT refined Analysis DATE: 20/10/20 22:29:25 GMT FROM: Phil Evans at U of Leicester A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and E. Ambrosi report on behalf of the Swift-XRT team: We have analysed 6.9 ks of XRT data for GRB 201020A (Ambrosi et al. GCN Circ. 28696), from 148 s to 35.3 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. 28698). The light curve can be modelled with a power-law decay with a decay index of alpha=0.71 (+/-0.04). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.06 (+0.18, -0.17). The best-fitting absorption column is 8.6 (+4.4, -3.9) x 10^20 cm^-2, in excess of the Galactic value of 3.7 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 3.2 x 10^-11 (3.9 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 8.6 (+4.4, -3.9) x 10^20 cm^-2 Galactic foreground: 3.7 x 10^20 cm^-2 Excess significance: 2.1 sigma Photon index: 2.06 (+0.18, -0.17) If the light curve continues to decay with a power-law decay index of 0.71, the count rate at T+24 hours will be 0.015 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.7 x 10^-13 (5.7 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/01000926. This circular is an official product of the Swift-XRT team.
GCN 28708 table
GRB_name GRB201020A
GCN_number 28708
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28708 SUBJECT: GRB 201020A: CrAO/ZTSH optical observations DATE: 20/10/21 00:03:22 GMT FROM: Alexei Pozanenko at IKI, Moscow N. Pankov (HSE), A. Pozanenko (IKI), V. Rumyantsev (CrAO), S. Belkin (IKI), A. Volnova (IKI) report on behalf of IKI GRB FuN: We observed the GRB 201020A (Ambrosi et al., GCN 28696) with ZTSH 2.6m telescope of CrAO observatory starting on Oct. 20 (UT) 16:06:30. The optical afterglow (Ambrosi et al., GCN 28696; Adachi et al., GCN 28697; Fu et al., GCN 28701; Belkin et al., GCN 28703) is clearly detected in R filter. Preliminary photometry of the afterglow in a combined image is following Date UT start t-T0 Filter Exp. OT err UL(3sigma) (mid, days) (s) 2018-10-20 16:06:30 0.42991 R 30*120 20.00 0.10 21.5 The photometry is based on several nearby USNO-B1.0 (R2) stars.
GCN 28711 table
GRB_name GRB201020A
GCN_number 28711
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28711 SUBJECT: GRB 201020A: GROWTH-India Telescope optical observations DATE: 20/10/21 02:17:35 GMT FROM: Varun Bhalerao at Indian Inst of Tech H. Kumar(IITB), J. Stanzin (IIA), V. Bhalerao(IITB), G. C. Anupama(IIA), S. Barway(IIA), report on behalf of the GROWTH-India collaboration: We followed up GRB 2010210A (E. Ambrosi et al., GCN #28696; also see:- R. Adachi et al., GCN #28697; J.P. Osborne et al., GCN #28698; V. Lipunov et al., GCN #27800, S.Y. Fu et al., GCN #28701; S. Belkin et al., GCN #28703 and T. Pankov et al., GCN #28708) with 0.7m GROWTH-India telescope. We obtained 300-sec exposures in the SDSS r’ filter starting at 2020-10-20T13:00:50.42 UT (~7.22 hrs after the burst). We clearly detected uncataloged sources at a position consistent with E. Ambrosi et al., GCN #28696. Here are the photometric results from GIT observations:- ------------------------------------------------------------------ JD (END) | T_end-T0(hrs) | Filter | Mag | ------------------------------------------------------------------ 2459143.04576 | 7.31 | r | 19.43 +/- 0.06 2459143.04943 | 7.39 | r | 19.49 +/- 0.05 2459143.05670 | 7.57 | r | 19.52 +/- 0.04 2459143.06046 | 7.66 | r | 19.59 +/- 0.04 2459143.06406 | 7.75 | r | 19.63 +/- 0.04 2459143.06764 | 7.83 | r | 19.65 +/- 0.04 ----------------------------------------------------------------- Combining our photometric results with r’ measurements of S.Y. Fu et al., (GCN #28701), S. Belkin et al., (GCN #28703), and T. Pankov et al., (GCN #28708) we conclude that the source is fading with a power-law index of 1.6 +/- 0.2. Given the fast fading, we encourage the follow-up of the source. The magnitudes are not corrected for galactic extinction. The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
GCN 28713 table
GRB_name GRB201020A
GCN_number 28713
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28713 SUBJECT: GRB 201020A: DOAO optical afterglow observations DATE: 20/10/21 04:51:18 GMT FROM: Gregory SungHak Paek at SNU Gregory S.H. Paek (CEOU/SNU), Myungshin Im (CEOU/SNU), Taewoo Kim, and Wonseok Kang (DOAO) on behalf of a larger collaboration We observed the optical counterpart of GRB 201020A (E. Ambrosi et al., GCN #28696; R. Adachi et al., GCN #28697; J.P. Osborne et al., GCN #28698; V. Lipunov et al., GCN #27800, S.Y. Fu et al., GCN #28701; S. Belkin et al., GCN #28703, T. Pankov et al., GCN #28708, and H. Kumar et al., GCN #28711) with the 1-m class telescope in Deokheung Optical Astronomy Observatory (DOAO). We calibrated flux with PS1 catalog and use AB magnitude system. --------------------------------------------------------------------- Mid Date[UT] Mid t-t0[days] Filter Exp.time[s] Mag Error --------------------------------------------------------------------- 2020-10-20 10:28:07 0.195 V 300*3 19.361 0.059 2020-10-20 10:33:21 0.199 R 300*3 19.006 0.042 2020-10-20 10:38:35 0.202 I 300*3 18.767 0.039 t0 : 2020-10-20 05:47:26 UT (E. Ambrosi et al., GCN #28696) The magnitudes are not corrected for galactic extinction.
GCN 28717 table
GRB_name GRB201020A
GCN_number 28717
Detection_method Other
redshift 2.9030
Circular_text TITLE: GCN CIRCULAR NUMBER: 28717 SUBJECT: GRB 201020A: Redshift from GTC/OSIRIS DATE: 20/10/21 10:30:41 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), M. Blazek, J. F. Agui Fernandez, C. C. Thoene (all HETH/IAA-CSIC), G. Lombardi (GRANTECAN, IAC) and A. Tejero (GRANTECAN) report: We observed the afterglow (Ambrosi et al., GCN#28696; Adachi et al., GCN#28697; Fu et al., GCN#28701; Belkin et al., GCN#28703; Pankov et al., GCN#28708; Kumar et al., GCN#28711; Paek et al., GCN#28713) of GRB 201020A (Ambrosi et al., GCN#28696; Sakamoto et al., GCN#28705; Bissaldi et al., GCN#28706) with the 10.4m GTC telescope, at Roque de los Muchachos Observatory (La Palma, Spain) equipped with OSIRIS. The observation started on 20 October 2020 at 20:08 UT (14.34 hrs after the GRB onset) and consisted of 4 x 900s with the R1000B grism, covering the wavelength range between 3700 and 7800 AA. Observations were taken under inclement conditions, with bad seeing and thick clouds passing through. The spectrum shows a clear continuum, consistent with the Lyman forest, Ly-alpha, SiII, OI, CII, SiIV, CIV, FeII, FeII*, and AlII, all at a common redshift of z = 2.903, which we identify as the redshift of the GRB.
GCN 28737 table
GRB_name GRB201020A
GCN_number 28737
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28737 SUBJECT: GRB 201020A: VIRT optical observations DATE: 20/10/22 02:04:54 GMT FROM: Priyadarshini Gokuldass at U. of the Virgin Islands P. Gokuldass (UVI), R. Strausbaugh (UVI), N. Orange (OrangeWave Innovative Science, LLC), D. Morris (UVI), A. Cucchiara (UVI/College of Marin) report: We observed the field of GRB201020A (Ambrosi et al., GCN 28696) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 10-20-2020 starting at 23:11:52.3 UT (T+17.2 hrs). We performed a series of exposures in R filter with a total exposure of 3140 s. The weather conditions were clear during the hours of observation with an average airmass of 2.1. We find no new source within the enhanced XRT position error circle (Osborne et al., 28698) and report the following 3-sigma upper limit: T_mid ||Exposure ||Filter ||Limit T+18 hrs ||3140s ||R ||>20.6 The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. The VIRT is still in the commissioning phase. This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR AST Award 1901296, and NSF HBCU-UP AST Award 1831682. This message can be cited.
GCN 28742 table
GRB_name GRB201020A
GCN_number 28742
Detection_method Swift-UVOT Det
ra 261.2278°
decl 31.4284°
redshift 2.9000
Circular_text TITLE: GCN CIRCULAR NUMBER: 28742 SUBJECT: GRB 201020A: Swift/UVOT Observations DATE: 20/10/22 12:16:21 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and E. Ambrosi (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 201020A 144 s after the BAT trigger (Ambrosi et al., GCN Circ. 28696). We confirm the fading source initially reported by Ambrosi et al. and since confirmed by numerous observations (Adachi et al., GCN Circ. 28697; Fu et al., GCN Circ. 28701; Belkin et al., GCN Circ. 28703, Pankow et al. GCN Circ. 28708, Kumar et al. GCN Circ. 28711, Paek et al. GCN Circ. 28713). The afterglow is not detected in UVOT's NUV filters, which would be consistent with the redshift of 2.9 reported by Kann et al. (GCN Circ. 28717). The preliminary UVOT position is: RA (J2000) = 17:24:54.66 = 261.22773 (deg.) Dec (J2000) = +31:25:42.1 = 31.42837 (deg.) with an estimated uncertainty of 0.44 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 (fc) 145 294 147 18.19+/-0.05 white 583 775 38 19.39+/-0.23 white 9805 10713 885 19.71+/-0.09 white 131168 131712 531 >21.48 v 632 826 38 17.91+/-0.28 v 21653 22150 485 19.26+/-0.28 v 34473 35292 798 19.86+/-0.29 v 125782 126429 629 >19.99 b 558 750 38 >19.30 b 22822 23469 630 20.35+/-0.21 b 39219 39998 759 21.05+/-0.36 b 130256 131163 885 >20.60 u (fc) 303 552 245 19.76+/-0.27 u 706 726 19 >18.42 u 29427 29557 128 >19.69 uvw1 681 876 38 >18.16 uvw1 28521 29420 885 >20.42 uvm2 656 676 19 >17.06 uvm2 27614 28514 885 >20.29 uvw2 608 800 38 >18.04 uvw2 10719 34466 1329 >20.71 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 28744 table
GRB_name GRB201020A
GCN_number 28744
Detection_method Konus-Wind Det
t_trigger 5:47:26.160 UTC
redshift 2.9030
Circular_text TITLE: GCN CIRCULAR NUMBER: 28744 SUBJECT: Konus-Wind detection of GRB 201020A DATE: 20/10/22 12:51:04 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 201020A (Swift-BAT trigger #1000926: Ambrosi et al., GCN 28696; Sakamoto et al., GCN 28705; T0(BAT)=05:47:26.16 UT; Fermi-GBM observation: Bissaldi et al., GCN 28706) was detected by Konus-Wind (KW) in the waiting mode. The burst light curve shows a single emission episode with a duration of ~ 15 s. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB201020A/ As observed by Konus-Wind, the burst had a fluence of 1.38(-0.23,0.45)x10^-6 erg/cm2 and a 2.944-s peak flux, measured from ~T0(BAT)+16.5 s, of 1.34(-0.28,+0.47)x10^-7 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The K-W 3-channel time-integrated spectrum (from ~T0(BAT)+10.6 s to ~T0(BAT)+25.3 s) is best described by simple power-law model with photon index of -2.41(-0.12,+0.17), chi2=0.06/1 dof. Assuming the redshift z=2.903 (Kann et al., GCN 28717) and a standard cosmology model with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~2.6x10^52 erg, and the peak luminosity L_iso is ~1.0x10^52 erg/s. All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.
GCN 28747 table
GRB_name GRB201020A
GCN_number 28747
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28747 SUBJECT: GRB 201020A: GROWTH-India Telescope late-time optical upper limit DATE: 20/10/22 15:21:06 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), J. Stanzin (IAO), V. Bhalerao(IITB), G. C. Anupama (IIA), S. Barway (IIA), report on behalf of the GROWTH-India collaboration: We observed GRB 201020A reported by Swift-BAT (E. Ambrosi et al., GCN #28696) with 0.7m GROWTH-India telescope. The field was observed in the SDSS r’ filter with multiple 300-sec exposures. We obtained the following late time upper limit: ---------------------------------------------------------------------- JD (mean)| T-T0(hrs) | Filter | Exposure (sec) | Lim_mag (5-sigma) | ---------------------------------------------------------------------- 2459144.094375 | 32.47 | r’ | 14 * 300 (stacked) | > 21.47 | ---------------------------------------------------------------------- This upper limit is consistent with our best-fit power-law decay from H. Kumar et al., GCN #28711. Magnitudes are in the AB system and calibrated against PanSTARRs PS1 data release, (Flewelling et al., 2018). The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
GCN 28789 table
GRB_name GRB201020A
GCN_number 28789
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28789 SUBJECT: GRB 201020A: 1.3m DFOT, optical upper limits DATE: 20/10/27 05:34:21 GMT FROM: Amit Kumar at ARIES, India Amit Kumar (ARIES), Rahul Gupta (ARIES), Ankur Ghosh (ARIES), Dimple (ARIES), Kaushal Sharma (ARIES), Amar Aryan (ARIES), Shashi B. Pandey (ARIES), and Kuntal Misra (ARIES) report: We observed the field of GRB 201020A (E. Ambrosi et al., GCN 28696) with the 1.3m Devasthal Fast Optical Telescope (DFOT) at Devasthal observatory of Aryabhatta Research Institute of observational sciencES (ARIES), India. Multiple frames of the GRB field were obtained in the Bessel R and I-bands (15*120sec in each filter). Preliminary photometry on stacked images were performed and calibrated against nearby USNO-B1 stars. We do not detect any OT candidate (see Adachi et al. GCN 28697; Lipunov et al. GCN 28700; Fu et al. GCN 28701; Belkin et al. 28703; Pankov et al. GCN 28708; Kumar et al. GCN 28711; Paek et al. 28713; Kann et al. 28717; Gokuldass et al. 28737; Siegel et al. 28742 and Kumar et al. GCN 28747) within the enhanced XRT position (Osborne et al., GCN 28698). The 3-sigma upper limits at the location of the afterglow are as follows: DATE Start UT Filter Exposure(sec) Lim_mag (3-sigma) 2020-10-24 12:51:08 I 15*120 >22.1 2020-10-24 13:23:45 R 15*120 >22.5 The estimated magnitudes have not been corrected for the Galactic extinction in the direction of the GRB. This massage may be cited.