//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26101 SUBJECT: GRB 191031A: Swift detection of a burst DATE: 19/10/31 00:45:49 GMT FROM: David Palmer at LANL A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC), J. A. Kennea (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 00:36:33 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 191031A (trigger=932435). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 233.470, +6.144 which is RA(J2000) = 15h 33m 53s Dec(J2000) = +06d 08' 37" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 50 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~2 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 23:18 UT on 2019 December 22. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is A. D'Ai (antonino.dai 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26102 SUBJECT: GRB 191031A: Fermi GBM Final Real-time Localization DATE: 19/10/31 00:46:50 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 00:36:35 UT on 31 Oct 2019, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 191031A (trigger 594175000.608294 / 191031025). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 247.3, Dec = 22.1 (J2000 degrees, equivalent to J2000 16h 29m, 22d 06'), with a statistical uncertainty of 12.9 degrees. The angle from the Fermi LAT boresight is 93.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191031025/quicklook/glg_skymap_all_bn191031025.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191031025/quicklook/glg_healpix_all_bn191031025.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191031025/quicklook/glg_lc_medres34_bn191031025.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26103 SUBJECT: GRB 191031A: COATLI Optical Observations DATE: 19/10/31 03:43:46 GMT FROM: Alan M Watson at UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Diego González (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra (UNAM), and Eleonora Troja (GSFC) report: We observed the field of GRB 191031A (D'Ai et al., GCN Circ. 26101; Fermi GBM Team, GCN Circ. 26102) with the COATLI 50-cm telescope and interim imager at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir (http://coatli.astroscu.unam.mx) from 2019-10-31 02:14 UTC (1.63 hours after the trigger) to 02:25, obtaining a total of 540 seconds of exposure in the w filter. The observations were taken at airmasses between 6.4 and 8.3. We do not detetect any uncataloged sources in the BAT error region to a 10-sigma limit of w = 18.75. Our w magnitudes are calibrated against the Pan-STARRS1 catalog, are on an approximate AB system (Becerra et al., 2019, ApJ, 872, 118), and are not corrected for Galactic extinction in the direction of the GRB. We thank the COATLI technical team and the staff of the Observatorio Astronómico Nacional. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26113 SUBJECT: Swift GRB191031.89: Global MASTER-Net observations report DATE: 19/10/31 22:09:22 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 (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), 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 GRB191031.89 (trigger No 932608,18h 53m 06.000s , +47d 38m 20.40s, R=0.05) errorbox 14 sec after notice time and 551 sec after trigger time at 2019-10-31 21:32:42 UT, with upper limit up to 17.4 mag. The observations began at zenith distance = 71 deg. The sun altitude is -60.1 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) was pointed to the Swift GRB191031.89 errorbox 48 sec after notice time and 585 sec after trigger time at 2019-10-31 21:33:17 UT, with upper limit up to 19.0 mag. The observations began at zenith distance = 53 deg. The sun altitude is -43.2 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1183931 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 607 | MASTER-Tavrida | C | 110 | 16.9 | 762 | MASTER-Tavrida | C | 420 | 17.4 | Coadd 646 | MASTER-IAC | P| | 120 | 18.4 | 811 | MASTER-IAC | P| | 450 | 19.0 | Coadd 646 | MASTER-IAC | P- | 120 | 18.3 | 745 | MASTER-Tavrida | C | 140 | 16.7 | 808 | MASTER-IAC | P| | 150 | 18.5 | 808 | MASTER-IAC | P- | 150 | 18.4 | 914 | MASTER-Tavrida | C | 170 | 16.5 | 1013 | MASTER-IAC | P| | 180 | 18.4 | 1013 | MASTER-IAC | P- | 180 | 18.3 | 1103 | MASTER-Tavrida | C | 180 | 16.0 | 1103 | MASTER-Tavrida | C | 180 | 15.5 | 1255 | MASTER-IAC | P| | 180 | 18.5 | 1255 | MASTER-IAC | P- | 180 | 18.3 | 1304 | MASTER-Tavrida | C | 180 | 16.1 | 1304 | MASTER-Tavrida | C | 180 | 15.7 | 1498 | MASTER-IAC | P- | 180 | 18.3 | 1498 | MASTER-IAC | P| | 180 | 18.3 | 1505 | MASTER-Tavrida | C | 180 | 15.9 | 1505 | MASTER-Tavrida | C | 180 | 14.8 | 1706 | MASTER-Tavrida | C | 180 | 15.0 | 1706 | MASTER-Tavrida | C | 180 | 14.1 | 1738 | MASTER-IAC | P| | 180 | 14.8 | 1738 | MASTER-IAC | P- | 180 | 14.7 | 1907 | MASTER-Tavrida | C | 180 | 14.3 | 1907 | MASTER-Tavrida | C | 180 | 15.8 | 1989 | MASTER-IAC | P| | 180 | 18.4 | 1989 | MASTER-IAC | P- | 180 | 18.2 | 2108 | MASTER-Tavrida | C | 180 | 16.6 | 2108 | MASTER-Tavrida | C | 180 | 16.6 | 2230 | MASTER-IAC | P- | 180 | 18.1 | 2230 | MASTER-IAC | P| | 180 | 18.2 | 2309 | MASTER-Tavrida | C | 180 | 17.2 | 2309 | MASTER-Tavrida | C | 180 | 17.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26116 SUBJECT: GRB 191031A: Fermi GBM detection DATE: 19/10/31 23:56:09 GMT FROM: Rachel Hamburg at UAH S. Lesage (UAH), R. Hamburg (UAH), and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 00:36:35.61 UT on 31 October 2019, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 191031A (trigger 594175000 / 191031025) which was also detected by the Swift/BAT (D'Ai et al. 2019, GCN 26101) The Fermi GBM Final Real-time Localization (GCN 26102) is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 106 degrees. The GBM light curve shows two pulses with a duration (T90) of about 200 s (50-300 keV). The time-averaged spectrum of the first pulse from T0-10.24 s to T0+10.24 s is best fit by a power law with an exponential high-energy cutoff. The power law index is -0.9 +/- 0.2 and the cutoff energy, parameterized as Epeak, is 218 +/- 57 keV. The time-averaged spectrum of the second pulse from T+174.08 to T0+197.64 is best fit by the same function with an index of -1.1 +/- 0.1 and an Epeak of 242 +/- 48 keV. The event fluence (10-1000 keV) in the time interval of the two pulses is (6.6 +/- 0.6)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+175.56 s in the 10-1000 keV band is 2.5 +/- 0.3 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: 26131 SUBJECT: GRB 191031A: Swift-BAT refined analysis DATE: 19/11/01 19:05:44 GMT FROM: Hans Krimm at NSF/NASA-GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), 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-61 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 191031A (trigger #932435) (D'Ai, et al., GCN Circ. 26101). The BAT ground-calculated position is RA, Dec = 233.490, 6.109 deg which is RA(J2000) = 15h 33m 57.7s Dec(J2000) = +06d 06' 32.9" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%. The mask-weighted light curve shows a single pulse with some overlying structure. The emission starts at ~T-8 sec, peaks at T+3 sec, and decays to background by ~T+18 sec. A pre-planned spacecraft slew took the burst location out of the field of view by T+95 sec. T90 (15-350 keV) is 19.1 +- 6.3 sec (estimated error including systematics). The time-averaged spectrum from T-11.08 to T+16.87 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.38 +- 0.19. The fluence in the 15-150 keV band is 9.0 +- 1.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+3.48 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/932435/BA/