//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28607 SUBJECT: GRB 201013A: Swift detection of a burst DATE: 20/10/13 04:01:49 GMT FROM: Kim Page at U.of Leicester K. L. Page (U Leicester), S. D. Barthelmy (GSFC), N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 03:46:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201013A (trigger=999948). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 107.388, +57.036 which is RA(J2000) = 07h 09m 33s Dec(J2000) = +57d 02' 09" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 15 sec. The peak count rate was ~29000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 03:47:39.9 UT, 69.3 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 107.3945, 57.0347 which is equivalent to: RA(J2000) = 07h 09m 34.69s Dec(J2000) = +57d 02' 05.0" with an uncertainty of 2.4 arcseconds (radius, 90% containment). This location is 13 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 does not constrain the column density. UVOT took a finding chart exposure of 150 seconds with the White filter starting 73 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05. 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28608 SUBJECT: GRB 201013A: Enhanced Swift-XRT position DATE: 20/10/13 08:40:14 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 2464 s of XRT Photon Counting mode data and 6 UVOT images for GRB 201013A, 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 = 107.39425, +57.03422 which is equivalent to: RA (J2000): 07h 09m 34.62s Dec (J2000): +57d 02' 03.2" with an uncertainty of 1.9 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28611 SUBJECT: GRB 201013A: Swift-XRT refined Analysis DATE: 20/10/13 16:49:45 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (ASDC), V. D'Elia (ASDC), B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), J.P. Osborne (U. Leicester) and K.L. Page report on behalf of the Swift-XRT team: We have analysed 6.3 ks of XRT data for GRB 201013A (Page et al. GCN Circ. 28607), from 89 s to 41.3 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 28608). The light curve can be modelled with a power-law decay with a decay index of alpha=0.86 (+/-0.03). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.08 (+0.30, -0.29). The best-fitting absorption column is 4.8 (+/-0.8) x 10^22 cm^-2, in excess of the Galactic value of 5.4 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 8.0 x 10^-11 (2.4 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.8 (+/-0.8) x 10^22 cm^-2 Galactic foreground: 5.4 x 10^20 cm^-2 Excess significance: 10.4 sigma Photon index: 2.08 (+0.30, -0.29) If the light curve continues to decay with a power-law decay index of 0.86, the count rate at T+24 hours will be 0.012 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.4 x 10^-13 (2.8 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/00999948. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28612 SUBJECT: Swift GRB 201013A: Global MASTER-Net observations report DATE: 20/10/13 18:12:10 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 201013A ( K. L. Page et al., GCN 28607) errorbox 51437 sec after notice time and 51478 sec after trigger time at 2020-10-13 18:04:29 UT, with upper limit up to 18.1 mag. The observations began at zenith distance = 73 deg. The sun altitude is -33.0 deg. The galactic latitude b = 25 deg., longitude l = 160 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1460562 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 51569 | MASTER-Tavrida | C | 180 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28613 SUBJECT: GRB 201013A: Swift/UVOT Upper Limits DATE: 20/10/13 19:41:14 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) 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 201013A 74 s after the BAT trigger (Page et al., GCN Circ. 28607). There is a bright optical source (USNO B1.0 1470-0207304) 0.5 arcsec from the enhanced XRT position (Beardmore et al. GCN Circ. 28608). The magnitudes measured at this position by UVOT are consistent with those catalogued and thus we do not detect any evidence of an afterglow candidate. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 74 223 147 >16.8 u_FC 286 535 246 >16.7 white 74 1712 412 >16.8 v 616 1763 136 >16.2 b 541 1686 117 >16.6 u 286 1662 343 >16.7 w1 665 1804 127 >16.6 m2 640 1611 58 >16.7 w2 591 1738 136 >17.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28614 SUBJECT: GRB 201013A: Swift-BAT refined analysis DATE: 20/10/13 21:21:05 GMT FROM: Amy Lien at GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), A. Y. Lien (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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201013A (trigger #999948) (Page et al., GCN Circ. 28607). The BAT ground-calculated position is RA, Dec = 107.392, 57.031 deg which is RA(J2000) = 07h 09m 34.1s Dec(J2000) = +57d 01' 52.4" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 64%. The mask-weighted light curve shows a double-peaked structure that starts at ~T-1 s and ends at ~T+10 s. The two main peaks occur at ~T+0.5 s and ~T+6.5 s, respectively. T90 (15-350 keV) is 7.36 +- 0.18 sec (estimated error including systematics). The time-averaged spectrum from T-0.85 to T+9.64 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.22 +- 0.04. The fluence in the 15-150 keV band is 6.7 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.05 sec in the 15-150 keV band is 24.6 +- 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/999948/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28615 SUBJECT: GRB 201013A: FRAM-ORM possible afterglow candidate DATE: 20/10/13 22:47:15 GMT FROM: Martin Jelinek at Astro.Inst-AVCR,Ondrejov Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ), Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek, Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza (Institute of Physics, Prague, CZ) report: The 25cm robotic telescope FRAM-ORM at La Palma (Spain) reacted robotically to the alert of GRB201013A (Page et al GCNC 28607), obtaining a series of 20 s unfiltered images starting at 03:47:01.3 UT, i.e. 31.3s post trigger. There is a relatively bright star (R~16.3) within the errorbox of the XRT localization. With the relatively coarse resolution of the 25 cm telescope, direct detection of a faint object within the XRT errorbox is impossible. We performed aperture photometry of the star. There seems to be an excess flux of ~3.5 sigma by ~ 570 s post trigger. This is when optical afterglows often show maxima in their lightcurves. We also performed image subtraction of a sum of four images obtained at the time of the detected peak and twelve latest images of the series. The resulting frame contains a very weak residual towards the position of the X-ray afterglow from the star center. We therefore conclude that there is a slight possibility of an afterglow peaking at R~17.0, which was outshined by a nearby star of R~16.3. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28618 SUBJECT: GRB 201013A: CALET Gamma-Ray Burst Monitor detection DATE: 20/10/14 10:11:51 GMT FROM: Valentin Pal'shin at AGU T. Tamura (Kanagawa 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, K. Kobayashi (Waseda U), Y. Shimizu (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 Swift GRB 201013A (Page et al., GCN Circ. 28607, Laha et al., GCN Circ. 28614; https://gcn.gsfc.nasa.gov/other/201013A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 03:46:29.773 UTC on 13 October 2020 (http://cgbm.calet.jp/cgbm_trigger/flight/1286595863/). The burst signal was seen by all CGBM detectors. The burst light curve shows a double-peaked structure which starts at T+0.5 sec and ends at T+7.5 sec. The T90 and T50 durations measured by the SGM data are 6.4 +- 0.4 sec and 1.9 +- 0.6 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1286595863/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28620 SUBJECT: GRB 201013A: AstroSat CZTI detection DATE: 20/10/14 16:05:33 GMT FROM: Soumya Gupta at IUCAA/ASTROSAT S. Gupta, V. Sharma A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed detection of a long GRB 201013A, which was also detected by Swift (Page K. et al., GCN #28607), Swift-XRT (Beardmore A. et al., GCN #28608), Global MASTER-Net (Lipunov V. et al., GCN #28612), Swift/UVOT (Breeveld A. et al., GCN #28613), Swift-BAT (Laha S. et al., GCN #28614), FRAM-ORM (Jelinek M. et al., GCN #28615) and CALET (Tamura T. et al., GCN #28618). The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-13 03:46:32.000 UT. The measured peak count rate associated with the burst is 631 +/- 39 cts/s above the background in the combined data of four quadrants, with a total of 3054 +/- 43 cts. The local mean background count rate was 586 +/- 17 cts/s. Using cumulative rates, we measure a T90 of 11.08 +/- 0.03 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 2020-10-13 03:46:29.500 UT. The measured peak count rate is 1229 +/- 53 cts/s above the background in the combined Veto data of four quadrants, with a total of 4458 +/- 55 cts. The local mean background count rate was 1131 +/- 22 cts/s. We measure a T90 of 11.63 +/- 0.01 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. 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28621 SUBJECT: GRB 201013A: TSHAO and AbAO optical observations, afterglow confirmation DATE: 20/10/14 16:20:40 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), V. Kim (AFIF, Pulkovo Observatory), R. Ya. Inasaridze (AbAO), M. Krugov (AFIF), A. Volnova (IKI) report on behalf of IKI-GRB-FuN: We observed the field of Swift GRB 201013A (Page et al., GCN 28607; see also detection by CALET Tamura et al, GCN 28618) with Zeiss-1000(W) 1-m telescope of Tien Shan Astronomical Observatory (TSHAO) and AS-32 telescope of Abastumani observatory (AbAO) in R-filter. Within enhanced XRT position (Beardmore et al., GCN 28608), at 1.6 arc seconds from the center of the position, we observed an object mentioned by Jelinek et al. (GCN 28615) and listed at least in the USNO-B.10 and PS1 catalogs. Aperture photometry of the object are brighter than R2=16.22 magnitude of the object in USNO-B1.0 1470-0207304 in both our observations. Flux subtraction of our photometry and R2=16.22 result in photometry of possible afterglow suggested in earlier observations by FRAM-ORM (Jelinek et al. GCN 28615). Results of the flux subtraction assuming negligible error of R2 presented in USNO-B1.0 are following Date, UT start, T0+ Exp., Filter, OT, Err., UL, observatory (mid, days) 2020-10-13 21:44:47 0.79464 22*360 R 19.00 (+0.22 -0.18) 20.0 TSHAO 2020-10-13 23:33:56 0.84197 50* 60 R 19.39 (+0.08 -0.08) 21.3 AbAO The photometry is based on nearby USNO-B1.0 star USNO-B1.0_id R2 1470-0207278 14.89 While we cannot definitely detect fading the possible afterglow, the brightness of possible afterglow faded significantly between earlier (Jelinek et al. GCN 28615) and our observations. The cross section profile of the object in our observation at Zeiss-1000(W) of TSHAO is differ from point like source. The reason of the extended profile might be due to offset of the afterglow from the foreground star or could be due to the object USNO-B1.0 1470-0207304 is not the star but a galaxy. In the latter case, USNO-B1.0 may be a small neighboring host galaxy GRB 201013A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28625 SUBJECT: GRB 201013A: Insight-HXMT/HE detection DATE: 20/10/15 09:03:21 GMT FROM: Y Q Zhang at IHEP C. Zheng, C. Cai, J. C. Liu, Q. Luo, S. Xiao, W. C. Xue, Q. B. Yi, Y. Q. Zhang, Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, X. Y. Song, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2020-10-13T03:46:30.200 (T0), Insight-HXMT/HE detected GRB 201013A (trigger ID: HEB201013157) in a routine search of the data, which also triggered Swift/BAT (Page K. L. et al., GCN #28607) and CALET (Tamura T. et al., GCN #28618). The Insight-HXMT/HE light curve mainly consists of multiple pulses with a duration (T90) of 6.77 s measured from T0+0.23 s. The 1-ms peak rate, measured from T0+0.53 s, is 20268 cnts/sec. The total counts from this burst is 31971 counts. URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB201013157_lc.jpg All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28652 SUBJECT: Konus-Wind observation of GRB 201013A DATE: 20/10/16 13:12:24 GMT FROM: Dmitry Frederiks at Ioffe Institute A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Lysenko, A. Ridnaia and T. Cline on behalf of the Konus-Wind team, report: The long-duration, bright GRB201013A (Swift/BAT detection: Page et al., GCN 28607; Laha et la., GCN 28614; CALET Gamma-Ray Burst Monitor detection: Tamura et al., GCN 28618; AstroSat CZTI detection: Gupta et al., GCN 28620; Insight-HXMT/HE detection: Zheng et al., GCN 28625) triggered Konus-Wind at T0=13589.476 s UT (03:46:29.476). The burst light curve shows a double-peaked structure which starts at ~T0-0.2 s and has a total duration of~11.4 s The emission is seen up to ~3 MeV. As observed by Konus-Wind, the burst had a fluence of 2.77(-0.33,+0.37)x10^-5 erg/cm2, and a 64-ms peak energy flux, measured from T0+0.768 s, of 1.64(-0.26,+0.27)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+9.216 s) is best fit in the 20 keV - 3 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.79(-0.13,+0.17), the high energy photon index beta = -2.24(-0.21,+0.15), the peak energy Ep = 212(-31,+32) keV, chi2 = 73/65 dof. The spectrum near the peak count rate (measured from T0 to T0+1.024 s) is best fit in the 20 keV - 3 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.49(-0.14,+0.16), the high energy photon index beta = -2.50(-0.35,+0.20), the peak energy Ep = 308(-39,+46) keV, chi2 = 75/57 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB201013_T13589/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28686 SUBJECT: GRB 201013A: 3.6m DOT Optical Observations DATE: 20/10/19 14:42:24 GMT FROM: Rahul Gupta at ARIES, India R. Gupta (ARIES), A. Kumar (ARIES), Dimple (ARIES), A. Ghosh (ARIES), A. Aryan (ARIES), B. Kumar (ARIES), S. B. Pandey (ARIES), and K. Misra (ARIES) report: We observed the XRT localized GRB 201013A detected by Swift-BAT (Beardmore et al., GCN 28608, Page et al., GCN 28607; see also: Laha et al., GCN 28614; Tamura et al., GCN 28618; Gupta et al., GCN 28620; Zheng et al., GCN 28625; Tsvetkova et al., GCN 28652) using the 4Kx4K CCD Imager (Pandey et al. 2018, 2018BSRSL..87...42P) mounted at the axial port of the 3.6m Devasthal Optical Telescope of ARIES Nainital on 13 th and 14 th October 2020. Multiple frames having exposure times of 300s each were taken in B and R filters. The measured magnitudes of the bright optical object (USNO-B1.0 1470-0207304) present within the XRT error circle (Beardmore et al., GCN 28608) are consistent with those reported in the USNO-B1.0 catalog (Rmag2=16.22, Bmag2= 16.49) in both the filters. We do not find any evidence of an afterglow candidate in the close vicinity. We obtain the following 3-sigma upper limits. Date UT start T-T0 Exp. Filter OT Err. UL Telescope (days) 2020-10-13 22:01:55 0.7607 3*300 R NA NA 23.2 3.6m DOT 2020-10-13 22:18:14 0.7720 3*300 B NA NA 23.5 3.6m DOT The limiting magnitudes quoted are not corrected for the Galactic and Host extinction in the direction of the burst. 3.6m Devasthal Optical Telescope (DOT) is a recently commissioned facility in Northern Himalayan region of India (long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (https://www.aries.res.in). Authors of this GCN circular thankfully acknowledge consistent support from the staff members to run and maintain the 3.6m DOT. This circular may be cited.