//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25987 SUBJECT: GRB 191011A: Fermi GBM Final Real-time Localization DATE: 19/10/11 04:46:15 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 04:35:58 UT on 11 Oct 2019, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 191011A (trigger 592461363.582334 / 191011192). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 207.9, Dec = 57.8 (J2000 degrees, equivalent to J2000 13h 51m, 57d 47'), with a statistical uncertainty of 4.0 degrees. The angle from the Fermi LAT boresight is 169.0 degrees. The skymap can be found here: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191011192/quicklook/glg_skymap_all_bn191011192.png The HEALPix FITS file, including the estimated localization systematic, can be found here: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191011192/quicklook/glg_healpix_all_bn191011192.fit The GBM light curve can be found here: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191011192/quicklook/glg_lc_medres34_bn191011192.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25988 SUBJECT: GRB 191011A: Swift detection of a burst with an optical counterpart DATE: 19/10/11 04:46:45 GMT FROM: David Palmer at LANL S. L Laha (GSFC/UMBC/CRESST), C. Gronwall (PSU), J.D. Gropp (PSU), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), D. M. Palmer (LANL) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Neil Gehrels Swift Observatory Team: At 04:35:56 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 191011A (trigger=928924). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 44.724, -27.845 which is RA(J2000) = 02h 58m 54s Dec(J2000) = -27d 50' 40" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex peak structure with a duration of about 20 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 04:37:11.1 UT, 74.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 44.72679, -27.84594 which is equivalent to: RA(J2000) = 02h 58m 54.43s Dec(J2000) = -27d 50' 45.4" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 9.5 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 http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.54 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.8 (+3.35/-2.89) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 77 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 02:58:54.80 = 44.72832 DEC(J2000) = -27:50:43.5 = -27.84541 with a 90%-confidence error radius of about 0.83 arc sec. This position is 6.1 arc sec. from the center of the XRT error circle. The estimated magnitude is 20.20 with a 1-sigma error of about 0.19. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is S. L Laha (sib.laha AT gmail.com). 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: 25989 SUBJECT: Swift GRB191011.19: Global MASTER-Net OT detection DATE: 19/10/11 04:50:49 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, A.V. Krylov, I. Gorbunov, D. Vlasenko, F. Balakin Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk K. Ivanov, O. Gres, N.M. Budnev, S.Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University D. Buckley, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the GRB191011.19 14 sec after notice time and 34 sec after trigger time at 2019-10-11 04:36:30 UT. On our 3-th (30s exposure) set , obtained 148 sec after tigger time at 2019-10-11 04:38:25 UT, we found 1 optical transient within Swift error-box (ra=44.7208 dec=-27.845 r=0.05) brighter than 15.7. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 163 2019-10-11 04:38:25 30 (02h 58m 48.339s , -27d 51m 48.55s) 16.26 The OT has irregular early time behaviour since 410.7 till 643.2 seconds after the trigger. The 5-sigma upper limit has been about 15.7mag The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25990 SUBJECT: Swift GRB191011.19: Global MASTER-Net observations report DATE: 19/10/11 05:29:43 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-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 GRB191011.19 (trigger No 928924,02h 58m 53.640s , -27d 50m 41.28s, R=0.05) errorbox 67 sec after trigger time at 2019-10-11 04:37:04 UT, with upper limit up to 20.0 mag. The observations began at zenit distance = 62 deg. The sun altitude is -32.4 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB191011.19 errorbox 85 sec after trigger time at 2019-10-11 04:37:21 UT, with upper limit up to 18.3 mag. The observations began at zenit distance = 21 deg. The sun altitude is -52.0 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=1163457 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 73 | MASTER-IAC | P| | 10 | 16.9 | 98 | MASTER-IAC | P| | 60 | 18.1 | Coadd 438 | MASTER-IAC | P| | 740 | 20.0 | Coadd 73 | MASTER-IAC | P- | 10 | 16.5 | 98 | MASTER-IAC | P- | 60 | 17.7 | Coadd 438 | MASTER-IAC | P- | 740 | 19.6 | Coadd 95 | MASTER-OAFA | C | 20 | 16.3 | 130 | MASTER-OAFA | C | 90 | 17.2 | Coadd 410 | MASTER-OAFA | C | 650 | 18.3 | Coadd 125 | MASTER-IAC | P| | 20 | 17.6 | 125 | MASTER-IAC | P- | 20 | 17.0 | 164 | MASTER-OAFA | C | 30 | 16.2 | 174 | MASTER-IAC | P- | 30 | 17.2 | 174 | MASTER-IAC | P| | 30 | 17.8 | 232 | MASTER-IAC | P- | 40 | 17.5 | 297 | MASTER-IAC | P- | 170 | 18.5 | Coadd 232 | MASTER-IAC | P| | 40 | 18.0 | 297 | MASTER-IAC | P| | 170 | 18.9 | Coadd 243 | MASTER-OAFA | C | 40 | 16.6 | 311 | MASTER-IAC | P- | 60 | 17.8 | 311 | MASTER-IAC | P| | 60 | 18.2 | 338 | MASTER-OAFA | C | 60 | 16.8 | 433 | MASTER-OAFA | C | 250 | 17.6 | Coadd 400 | MASTER-IAC | P| | 70 | 18.4 | 400 | MASTER-IAC | P- | 70 | 17.8 | 451 | MASTER-OAFA | C | 80 | 16.5 | 499 | MASTER-IAC | P| | 90 | 18.6 | 624 | MASTER-IAC | P| | 340 | 19.5 | Coadd 499 | MASTER-IAC | P- | 90 | 18.3 | 624 | MASTER-IAC | P- | 340 | 19.3 | Coadd 588 | MASTER-OAFA | C | 110 | 17.2 | 621 | MASTER-IAC | P| | 110 | 18.5 | 621 | MASTER-IAC | P- | 110 | 18.4 | 756 | MASTER-OAFA | C | 140 | 17.4 | 931 | MASTER-OAFA | C | 490 | 18.1 | Coadd 766 | MASTER-IAC | P| | 140 | 18.7 | 766 | MASTER-IAC | P- | 140 | 18.5 | 940 | MASTER-IAC | P| | 170 | 18.9 | 1120 | MASTER-IAC | P| | 530 | 19.1 | Coadd 940 | MASTER-IAC | P- | 170 | 18.6 | 1120 | MASTER-IAC | P- | 530 | 18.9 | Coadd 956 | MASTER-OAFA | C | 170 | 17.5 | 1134 | MASTER-IAC | P| | 180 | 19.0 | 1134 | MASTER-IAC | P- | 180 | 18.6 | 1175 | MASTER-OAFA | C | 180 | 17.4 | 1382 | MASTER-IAC | P- | 180 | 18.6 | 1383 | MASTER-IAC | P| | 180 | 19.0 | 1399 | MASTER-OAFA | C | 180 | 17.0 | 1579 | MASTER-OAFA | C | 540 | 17.3 | Coadd 1625 | MASTER-OAFA | C | 180 | 16.5 | 1628 | MASTER-IAC | P| | 180 | 19.0 | 1628 | MASTER-IAC | P- | 180 | 18.7 | 1848 | MASTER-OAFA | C | 180 | 16.8 | 1873 | MASTER-IAC | P| | 180 | 19.0 | 1873 | MASTER-IAC | P- | 180 | 18.7 | 2068 | MASTER-OAFA | C | 180 | 16.9 | 2121 | MASTER-IAC | P| | 180 | 19.0 | 2121 | MASTER-IAC | P- | 180 | 18.8 | 2293 | MASTER-OAFA | C | 180 | 15.0 | 2372 | MASTER-IAC | P- | 180 | 18.7 | 2372 | MASTER-IAC | P| | 180 | 19.1 | 2516 | MASTER-OAFA | C | 180 | 12.8 | 2620 | MASTER-IAC | P- | 180 | 18.8 | 2620 | MASTER-IAC | P| | 180 | 19.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25991 SUBJECT: GRB 191011A: VLT X-shooter redshift from RRM Observations DATE: 19/10/11 06:19:02 GMT FROM: Alexander Kann at IAA-CSIC D. B. Malesani (DTU Space), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D. A. Kann (HETH/IAA-CSIC), V. D'Elia (SSDC), J. P. U. Fynbo (DAWN/NBI), and G. Pugliese (Univ. Amsterdam) report on behalf of the Stargate Consortium: We observed the localization of the Swift GRB 191011A (Laha et al., GCN 25988) with X-shooter on the VLT in RRM mode. The optical afterglow (Laha et al., GCN 25988, Lipunov et al., GCN 25989) is well-detected, and we measure a magnitude of r' = 19.18 +/- 0.06 mag (AB) from the 15 s acquisition image obtained starting at 2019-10-11T04:59:12.540, 23.28 min after the trigger, measured against PanSTARRS field stars. In the first spectrum (integration time 175 s) we detect Ly-a, SII, OI, SiII, CII, SiIV, CIV, FeII, CI, AlII, AlIII, MnII, MgII, MgI, and FeII*, all at a common redshift z=1.722. We consider this the redshift of GRB 191011A. We furthermore report the presence of an intervening MgII system at z=1.2072. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Chiara Mazzucchelli, Rodrigo Palominos, and Camila Navarrete. NB: We note the detection of a Fermi GRB (The Fermi GBM team, GCN 25987) at essentially the same time and with similar light curve structure, however, this GRB is localized to the northern hemisphere. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25992 SUBJECT: GRB 191011A: GROND Detection of the Optical/NIR afterglow DATE: 19/10/11 06:24:06 GMT FROM: Ana Nicuesa at TLS Tautenburg A. Nicuesa Guelbenzu (TLS Tautenburg) and P. Schady (Univ. of Bath) report: We observed the field of GRB 191011A (Swift trigger 928924; Laha et al., GCN 25988) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 04:38 UT on 2019-10-11, around 2 minutes after the GRB trigger and lasted for about 5 minutes. They were performed at an average seeing of 1.14" and at an average airmass of 1.1. We detect the optical afterglow candidate reported by Laha et al. (GCN 25988) and measure the following preliminary magnitudes and upper limits (AB magnitudes): r' = 19.52 +/- 0.1 mag, i' = 18.46 +/- 0.05 mag, z' = 18.62 +/- 0.1 mag, J = 17.89 +/- 0.1 mag, H = 17.21 +/- 0.1 mag. The optical afterglow is also visible in g' band. The magnitudes are calibrated against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.02 mag in the direction of the burst (Schlegel et al. 1998). We acknowledge the excellent support from Regis Lachaume in La Silla in acquiring these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25993 SUBJECT: GRB 191011A: BALROG localization (Fermi Trigger 592461363 / GRB 191011192) DATE: 19/10/11 06:29:51 GMT FROM: Jochen Greiner at MPE,Garching J. Burgess, F. Kunzweiler, B. Biltzinger, F. Berlato, & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 592461363 at 04:35:58 on 11 Oct. 2019 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position (1 sigma statistical errors) is: RA(2000.0) = 46.4+/-4.6 deg Decl.(2000.0) = -32.5+/-5.6 deg We estimate an additional systematic error of 2 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB191011192/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB191011192/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB191011192/json //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25994 SUBJECT: GRB 191011A: correction of reported magnitudes DATE: 19/10/11 08:09:21 GMT FROM: Ana Nicuesa at TLS Tautenburg A. Nicuesa Guelbenzu (TLS Tautenburg) reports: An error occurred in the previous data reduction. Corrected AB magnitudes are (midtime of the observations: 04:42 UT, Oct. 11): g' = 19.97 +/- 0.08 mag, r' = 19.46 +/- 0.05 mag, i' = 19.08 +/- 0.07 mag, z' = 18.79 +/- 0.10 mag, J = 18.79 +/- 0.06 mag, and H = 18.61 +/- 0.06 mag, calibrated against PanSTARRS and 2MASS field stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25995 SUBJECT: GRB 191011A: Enhanced Swift-XRT position DATE: 19/10/11 10:26:18 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 4075 s of XRT Photon Counting mode data and 7 UVOT images for GRB 191011A, 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 = 44.72800, -27.84540 which is equivalent to: RA (J2000): 02h 58m 54.72s Dec (J2000): -27d 50' 43.4" with an uncertainty of 1.5 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: 25996 SUBJECT: GRB 191011A: MASTER OT retraction. DATE: 19/10/11 10:49:05 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov Sternberg Astronomical Institute, Moscow State University The GRB 191011A optical transient candidate published by us in (Lipunov et. al. GCN 25989) is a group of hot pixels on a CCD matrix. This is not a real GRB afterglow candidate. We sorry for this mistake. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25998 SUBJECT: GRB 191011A: Swift-XRT refined Analysis DATE: 19/10/11 13:13:26 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (ASDC), V. D'Elia (ASDC), J.A. Kennea (PSU), B. Sbarufatti (PSU), D.N. Burrows (PSU) and S.L Laha report on behalf of the Swift-XRT team: We have analysed 7.1 ks of XRT data for GRB 191011A (L Laha et al. GCN Circ. 25988), from 84 s to 23.3 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 25995). The light curve can be modelled with an initial power-law decay with an index of alpha=0.15 (+0.15, -0.20), followed by a break at T+855 s to an alpha of 1.34 (+/-0.12). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.83 (+/-0.15). The best-fitting absorption column is 5.3 (+3.5, -3.1) x 10^21 cm^-2, at a redshift of 1.722, in addition to the Galactic value of 1.5 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 3.6 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 1.5 x 10^20 cm^-2 Intrinsic column: 5.3 (+3.5, -3.1) x 10^21 cm^-2 at z=1.722 Photon index: 1.83 (+/-0.15) If the light curve continues to decay with a power-law decay index of 1.34, the count rate at T+24 hours will be 1.0 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.7 x 10^-14 (4.2 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00928924. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26000 SUBJECT: GRB 191011A: Fermi GBM observation DATE: 19/10/11 14:23:34 GMT FROM: Peter Veres at UAH E. Bissaldi (Politecnico and INFN Bari) and P. Veres (UAH) report on behalf of the Fermi GBM Team: "At 04:35:58.58 UT on 11 October 2019, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 191011A (trigger 592461363 / 191011192), which was also detected by the Swift/BAT (Laha et al. 2019, GCN 25988). The GBM localization statistic exhibited two minima, one of which is consistent with the Swift location (75% containment). The localization centroid in the Real-time Localization notice (GCN 25987) is for the other minimum, which is near the Earth limb and is inconsistent with the Swift location. The angle from the Fermi LAT boresight at the GBM trigger time is 39 degrees. The GBM light curve shows several pulses with a duration (T90) of about 13 s (50-300 keV). The time-averaged spectrum from T0-2.0 s to T0-0.38 s is adequately fit by a simple power law function with index -1.76 +/- 0.08. The event fluence (10-1000 keV) in this time interval is (4.33 +/- 0.50)E-7 erg/cm^2. The 1-sec peak photon flux measured starting from T0-1.8 s in the 10-1000 keV band is 3.29 +/- 0.30 ph/s/cm^2. A power law function with an exponential high-energy cutoff fits the spectrum equally well. The power law index is -1.24 +/- 0.29 and the cutoff energy, parameterized as Epeak, is 89 +/- 23 keV. 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: 26001 SUBJECT: GRB 191011A: RATIR Optical and NIR Observations DATE: 19/10/11 15:41:42 GMT FROM: Alan M Watson at UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Diego González (UNAM), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report: We observed the field of GRB 191011A (Laha et al., GCN Circ. 25988) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2019/10 11.26 to 2019/10 11.48 UTC (1.60 to 6.94 hours after the BAT trigger), obtaining a total of 1.64 hours exposure in the i band and 0.49 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle, in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections and upper limits (3-sigma): i = 21.59 +/- 0.13 Z = 21.22 +/- 0.21 Y > 21.76 J > 19.81 H > 20.54 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26002 SUBJECT: GRB 191011A: Swift/UVOT Detection DATE: 19/10/11 17:23:17 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and Laha (GSFC/UMBC/CRESST) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 191011A 78 s after the BAT trigger (Laha et al., GCN Circ. 25988). A source consistent with the XRT position (Evans et al. GCN Circ. 25995) is detected in the initial UVOT exposures. This GRB was also detected by Fermi/GBM (GCN Circ. 25987,26000) and Insight-HXMT-HE(Yi et al, GCN Cir. 25997). A redshift was reported using the VLT/Xshooter (Kahn et al, GCN Circ.25991), while the optical afterglow was reported from Master (Lipunov et al, GCN Circ. 25990; GROND (Nicuesa Guelbenzu et al., GCN Circ. 25992). The preliminary UVOT position is: RA (J2000) = 02:58:54.79 = 44.72829 (deg.) Dec (J2000) = -27:50:43.4 = -27.84540 (deg.) with an estimated uncertainty of 0.73 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 78 228 147 20.27 +/- 0.16 v 620 11672 1211 >20.2 b 545 7080 510 21.03 +/- 0.27 u 290 6875 697 20.86 +/- 0.27 w1 670 6670 510 >20.3 m2 1073 12198 767 >21.1 w2 1024 7491 432 >20.9 The afterglow is seen to be nearly constant in the white filter until about 1000s, whereafter a decay is observed. 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: 26003 SUBJECT: GRB 191011A: Swift-BAT refined analysis DATE: 19/10/12 01:36:12 GMT FROM: Amy Lien at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), J. P. Norris (BSU), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU) (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 191011A (trigger #928924) (Laha et al., GCN Circ. 25988). The BAT ground-calculated position is RA, Dec = 44.729, -27.853 deg which is RA(J2000) = 02h 58m 55.0s Dec(J2000) = -27d 51' 12.4" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The mask-weighted light curve shows a short pulse that starts and peaks at ~T0, and ends at ~T+2 s. The short pulse is followed by some weak emission that lasts until ~T+8 s. T90 (15-350 keV) is 7.37 +- 0.95 sec (estimated error including systematics). The time-averaged spectrum from T-0.21 to T+8.04 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.94 +- 0.17. The fluence in the 15-150 keV band is 3.3 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.18 sec in the 15-150 keV band is 1.8 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. Using the 16-ms binned light curve, the spectral lag of the short pulse is 30 (+45, -34) ms for the 50-100 keV to 15-25 keV bands, and 20 (+40, -44) ms for the 25-50 keV to 15-25 keV bands. These values are consistent with both short and long GRBs due to the large uncertainties. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/928924/BA/