//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28803 SUBJECT: GRB 201029A: Swift detection of a burst DATE: 20/10/29 20:29:51 GMT FROM: David Palmer at LANL S. Dichiara (NASA/GSFC/UMCP), J. A. Kennea (PSU), N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST), F. E. Marshall (NASA/GSFC), M. J. Moss (GWU), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Tohuvavohu (U Toronto) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Neil Gehrels Swift Observatory Team: At 20:19:50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201029A (trigger=1003002). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 229.601, +44.464 which is RA(J2000) = 15h 18m 24s Dec(J2000) = +44d 27' 50" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single complex peak structure with a duration of about 40 sec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began observing the field at 20:21:52.3 UT, 122.3 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 229.58280, 44.45975 which is equivalent to: RA(J2000) = 15h 18m 19.87s Dec(J2000) = +44d 27' 35.1" with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 49 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. No spectrum from the promptly downlinked event data is yet available to determine the column density. The initial flux in the 2.5 s image was 7.42e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 131 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 0.02. Burst Advocate for this burst is S. Dichiara (dichiara AT umd.edu). 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: 28805 SUBJECT: GRB 201029A: FRAM-ORM optical limit DATE: 20/10/29 21:17:54 GMT FROM: Martin Jelinek at Astro.Inst-AVCR,Ondrejov Martin Jelinek, 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 Swift alert of GRB201029A (trigger=1003002; Dichiara et al., GCNC 28803), obtaining a series of 20s unfiltered images starting at 20:21:23.0UT, i.e. 93s post trigger. We do not detect any new source in the XRT error box neither in single images (3-sigma limit R>~15.7) nor in a combined 20x20s frame (mean exp time 276s post trigger, 3-sigma limit R>~18.15) similarly to Lipunov et al. (GCNC 28804). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28806 SUBJECT: GRB 201029A: Enhanced Swift-XRT position DATE: 20/10/29 22:07:05 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 764 s of XRT Photon Counting mode data and 1 UVOT images for GRB 201029A, 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 = 229.58157, +44.45927 which is equivalent to: RA (J2000): 15h 18m 19.58s Dec (J2000): +44d 27' 33.4" 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28807 SUBJECT: GRB 201029A: BOOTES-1 optical upper limit DATE: 20/10/30 07:09:24 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report: Following the Swift trigger of GRB 201029A (Dichiara et al., GCNC 28803), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this burst at 8 degrees above the horizon. Series images were taken started 20:21:26UT (~96 s after trigger). In the co-added of following images, no source is detected within the enhanced XRT position (Beardmore et al., GCNC 28806) which down to 17.7 mag (clear filter), which consistent with the non-detections reported by UVOT (Dichiara et al., GCNC 2828803) and FRAM-ORM (Jelinek et al., GCNC 28805). We thank the staff at INTA-CEDEA for their excellent support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28808 SUBJECT: GRB 201029A: Swift-XRT refined Analysis DATE: 20/10/30 10:11:05 GMT FROM: Phil Evans at U of Leicester M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and S. Dichiara (NASA/GSFC/UMCP) reporton behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 201029A (Dichiara et al. GCN Circ. 28803), from 128 s to 34.7 ks after the BAT trigger. The data comprise 764 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. 28806). The light curve is dominated by flares. The first flare covers ~T0+200-650 s. The second flare started at T0+1100s and was still ongoing when the GRB entered Earth eclipse at T0+1850 s. The third flare began at T0+11.5 ks, was still ongoing at T0+23 ks and finished at some point before T0+30.5 ks, although large observing gaps in this window prevent acccurate measurements of the flare and it is possible that there are multiple flares at this time rather than a single long-lived flare. This behaviour, of multiple flares dominating the XRT light curve for tens of kiloseconds, is reminiscent of GRBs 050904, 121027A and 130925A (see https://www.swift.ac.uk/xrt_curves/allcurves.php for a mugshot gallery of all XRT GRB afterglows). This flaring activity makes it difficult to model the underlying behaviour. Excluding all of the above times, the light curve can be modelled with a power-law decay with a decay index of alpha=0.79 (+0.05, -0.06). These formal errors are likely underestimates, since they depend on how accurate the estimates of flare times are, which are themselves subject to proper modelling of the underlying emission. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.65 (+/-0.05). The best-fitting absorption column is 4.9 (+/-0.3) x 10^21 cm^-2, in excess of the Galactic value of 2.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.97 (+/-0.12) and a best-fitting absorption column of 2.9 (+/-0.5) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (5.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.9 (+/-0.5) x 10^21 cm^-2 Galactic foreground: 2.1 x 10^20 cm^-2 Excess significance: 9.6 sigma Photon index: 1.97 (+/-0.12) If the light curve continues to decay with a power-law decay index of 0.79, the count rate at T+24 hours will be 0.024 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.2 x 10^-13 (1.3 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/01003002. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28809 SUBJECT: GRB 201029A: Fermi GBM detection DATE: 20/10/30 14:40:58 GMT FROM: Peter Veres at UAH P. Veres and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 20:19:51.61 UT on 29 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201029A (trigger 625695596 / 201029847) which was also detected by the Swift/BAT (Dichiara et al., GCN 28803). The GBM on-ground location 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 consists of a broad peak with a duration (T90) of about 78 s (50-300 keV). The time-averaged spectrum from T0-8.2 s to T0+34.8 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.03 +/- 0.10 and the cutoff energy, parameterized as Epeak, is 647 +/- 230 keV. The event fluence (10-1000 keV) in this time interval is (1.59 +/- 0.14)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.4 s in the 10-1000 keV band is 1.4 +/- 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/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28810 SUBJECT: GRB 201029A: Swift/UVOT Upper Limits DATE: 20/10/30 17:25:08 GMT FROM: Frank Marshall at Swift/UVOT F. E. Marshall (NASA/GSFC) and S. Dichiara (NASA/GSFC/UMCP) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 201029A 131 s after the BAT trigger (Dichiara et al., GCN Circ. 28803). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 28806) is detected in the initial UVOT exposures. 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 131 281 147 >20.6 u_FC 289 539 246 >19.9 white 131 1708 412 >21.4 v 619 1759 127 >19.2 b 545 1858 136 >19.9 u 289 1833 362 >20.0 w1 842 1808 97 >19.5 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). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28811 SUBJECT: Swift GRB 201029A: Global MASTER-Net observations report DATE: 20/10/30 20:21:58 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-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the Swift GRB 201029A ( S. Dichiara et al., GCN 28803) errorbox 103 sec after trigger time at 2020-10-29 20:23:35 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 77 deg. The sun altitude is -27.6 deg. The galactic latitude b = 56 deg., longitude l = 73 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1471870 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 113 | MASTER-IAC | C | 20 | 15.9 | 148 | MASTER-IAC | C | 90 | 16.6 | Coadd 338 | MASTER-IAC | C | 470 | 17.3 | Coadd 146 | MASTER-IAC | C | 30 | 16.0 | 197 | MASTER-IAC | C | 40 | 16.0 | 253 | MASTER-IAC | C | 50 | 16.3 | 343 | MASTER-IAC | C | 230 | 17.0 | Coadd 322 | MASTER-IAC | C | 60 | 16.4 | 672 | MASTER-IAC | C | 120 | 16.5 | 817 | MASTER-IAC | C | 150 | 16.6 | 997 | MASTER-IAC | C | 510 | 16.6 | Coadd 993 | MASTER-IAC | C | 180 | 16.4 | 1193 | MASTER-IAC | C | 180 | 16.4 | 1392 | MASTER-IAC | C | 180 | 16.1 | 1572 | MASTER-IAC | C | 540 | 16.6 | Coadd 1591 | MASTER-IAC | C | 180 | 16.0 | 1791 | MASTER-IAC | C | 180 | 15.9 | 1991 | MASTER-IAC | C | 180 | 15.7 | 2601 | MASTER-IAC | C | 180 | 15.3 | 83049 | MASTER-IAC | C | 60 | 16.8 | 84836 | MASTER-IAC | C | 60 | 16.5 | 85552 | MASTER-IAC | C | 60 | 16.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28813 SUBJECT: GRB 201029A: Swift-BAT refined analysis DATE: 20/10/30 20:48:43 GMT FROM: Sibasish Laha at GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), S. Dichiara (NASA/GSFC/UMCP), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), 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-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201029A (trigger #1003002) (S. Dichiara et al., GCN Circ. 28803). The BAT ground-calculated position is RA, Dec = 229.607, 44.473 deg which is RA(J2000) = 15h 18m 25.7s Dec(J2000) = +44d 28' 21.7" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The BAT light curve showed a complex structure with a duration of about 150 sec. T90 (15-350 keV) is 120.55 +- 9.54 sec (estimated error including systematics). The time-averaged spectrum from T-2.19 to T+133.11 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.09 +- 0.11. The fluence in the 15-150 keV band is 2.2 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+7.06 sec in the 15-150 keV band is 0.6 +- 0.1 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/1003002/BA/