//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18611 SUBJECT: GRB 151118A: Swift detection of a burst DATE: 15/11/18 03:24:39 GMT FROM: Scott Barthelmy at NASA/GSFC A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 03:06:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151118A (trigger=664078). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 57.158, +65.869, which is RA(J2000) = 03h 48m 38s Dec(J2000) = +65d 52' 07" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a few peaks with a duration of about 25 sec. The peak count rate was ~2600 counts/sec (15-350 keV), at ~6 sec after the trigger. The XRT began observing the field at 03:07:36.2 UT, 66.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 57.1719, 65.9012 which is equivalent to: RA(J2000) = 03h 48m 41.25s Dec(J2000) = +65d 54' 04.4" with an uncertainty of 2.4 arcseconds (radius, 90% containment). This location is 117 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.54 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.9 (+4.29/-3.55) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 250 seconds with the U filter starting 281 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 none of the XRT error circle. 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 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 1.10. Burst Advocate for this burst is A. Amaral-Rogers (aar14 AT le.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/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18612 SUBJECT: GRB 151118A: Optical observations from OSN DATE: 15/11/18 04:36:51 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), A. Sota (IAA-CSIC), and C. Thoene (IAA-CSIC) report: We observed the field of GRB 151118A (Amaral-Rogers et al. GCN 18611) with the 1.5 m OSN telescope in Granada (Spain), starting at 03:17:55 UT (11.42 min after the GRB onset). Observations consisted of 7x300 s exposures in I-band. No new source is detected within the XRT error box. The 3-sigma limiting magnitudes of the individual exposures, and the combined frames are I(Vega) = 21.5 mag, and I(Vega) = 22.5 mag, respectively. The mean time of the combined exposure is 03:37:49 (31.32 min after the burst). Photometry was obtained by comparison with stars from the USNO-B1.0 catalogue. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18613 SUBJECT: GRB GRB 151118A: MASTER-NET optical observations DATE: 15/11/18 11:11:38 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D. Vlasenko, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB151118.13 30 sec after notice time and 44 sec after trigger time at 2015-11-18 03:07:17 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=03 48 37 dec=+65 52 06 r=0.05). The 5-sigma upper limit has been about 16.5 mag unfiltered. MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB151118A 24 sec after notice time and 42 sec after trigger time at 2015-11-18 03:07:12 UT in two polarizations. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (Amaral-Rogers et al GCN 18611). Our early upper limits on single and coadd images given in a table below: Table 1. 5 sigma limit. T-Ts T-Tm Expt. P| P- coadd. lim lim ---------------------------------------- 42 47 10 16.7 16.8 1 42 90 50 17.9 18.0 3 42 508 790 19.9 20.0 12 86 96 20 17.3 17.4 1 117 127 20 17.3 17.4 1 147 218 120 18.7 18.8 3 299 420 220 19.2 19.3 3 551 762 400 19.6 19.7 3 --------------------------------------- T - is a trigger time [s]. Ts - image start time [s]. Tm - image middle time [s]. Expt - exposure time [s]. P| - image upper limit in polarizer orientated 90 deg. to RA axis [mag]. P- - image upper limit in polarizer orientated 0 deg. to RA axis [mag]. We do not see OT brighter 20 mag. There is marginal object (m~20) with 6" W (RA) and 3"S (dec) offset from XRT error box center (Ra = 03h 48m 40.40s Dec= 65d 54m 01.3s Mag ~ 20.3 +- 0.7 ). The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18614 SUBJECT: GRB 151118A: Enhanced Swift-XRT position DATE: 15/11/18 11:22:15 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 4427 s of XRT Photon Counting mode data and 6 UVOT images for GRB 151118A, 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 = 57.17172, +65.90168 which is equivalent to: RA (J2000): 03h 48m 41.21s Dec (J2000): +65d 54' 06.1" with an uncertainty of 1.6 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: 18615 SUBJECT: GRB 151118A: Swift/UVOT Upper Limits DATE: 15/11/18 12:31:35 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and Amaral-Rogers (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 151118A 70 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 18611). No optical afterglow consistent with the XRT position (Amaral-Rogers et al. GCN Circ. 18611) 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) 70 220 148 >20.6 u (fc) 282 532 246 >20.0 white 70 754 186 >20.8 v 612 631 19 >18.3 b 537 730 39 >19.3 u 282 705 265 >19.9 w1 661 680 19 >18.2 w2 587 607 19 >17.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.10 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18617 SUBJECT: GRB 151118A: Swift-XRT refined Analysis DATE: 15/11/18 12:44:51 GMT FROM: Phil Evans at U of Leicester C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. D'ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU) and A. Amaral-Rogers report on behalf of the Swift-XRT team: We have analysed 7.4 ks of XRT data for GRB 151118A (Amaral-Rogers et al. GCN Circ. 18611), from 52 s to 22.7 ks after the BAT trigger. The data comprise 22 s in Windowed Timing (WT) mode (the first 7 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 18614). The late-time light curve (from T0+4.9 ks) can be modelled with a power-law decay with a decay index of alpha=1.07 (+/-0.26). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.93 (+0.23, -0.22). The best-fitting absorption column is 1.07 (+0.25, -0.21) x 10^22 cm^-2, in excess of the Galactic value of 4.5 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.1 x 10^-11 (9.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.07 (+0.25, -0.21) x 10^22 cm^-2 Galactic foreground: 4.5 x 10^21 cm^-2 Excess significance: 4.7 sigma Photon index: 1.93 (+0.23, -0.22) If the light curve continues to decay with a power-law decay index of 1.07, the count rate at T+24 hours will be 4.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x 10^-13 (4.2 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/00664078. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18618 SUBJECT: GRB 151118A: ISON-NM early optical limit DATE: 15/11/18 14:44:20 GMT FROM: Alexei Pozanenko at IKI, Moscow L. Elenin (KIAM), A. Volnova (IKI), E. Mazaeva (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 151118A (Amaral-Rogers et al., GCN 18611) with 0.4-m telescope of ISON-NM observatory in robotic mode starting on Nov., 18 (UT) 03:08:32 i.e. 122 seconds after burst trigger. We obtained 6 unfiltered images of 30 s exposure under unfavorable weather conditions. We do not detect any source within enhanced XRT error circle (Evans et al., GCN 18614): Date UT start t-T0 Filter Exp. UL(3 sigma) (mid, days) (s) 2015-11-28 03:08:32 0.00158 None 1*30 17.4 2015-11-28 03:08:32 0.00265 None 5*30 18.0 The photometry is based on nearby USNO-B1.0 stars: USNO-B1.0 id R2 1559-0079254 15.66 1558-0078601 16.03 1558-0078636 14.62 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18619 SUBJECT: GRB 151118A: Early optical limit from pt5m, La Palma DATE: 15/11/18 17:56:51 GMT FROM: Liam K Hardy at U of Shffield L. K. Hardy (Sheffield), V. S. Dhillon (Sheffield, IAC), S. P. Littlefair (Sheffield), T. Butterley (Durham) and R. W. Wilson (Durham) report: Our automated robotic telescope 'pt5m' (Hardy et al. 2015, MNRAS 454, 4316) on La Palma observed the field of GRB 151118A (Amaral-Rogers et al., GCN 18611) starting at 03:16:27 UT on Nov 18, 10 min after the GRB detection. Observations comprised of 46 x 60-second exposures in the R-band. We detect no new source within the XRT error box (Evans et al., GCN 18614). The 3-sigma limiting magnitude of a combined image is R = 22.1 mag. The mean time of the combined exposure is 03:42 UT (36 mins after the burst). We obtained photometry using the nearest comparison star, USNOB1.0:1559-0079286, R=15.6. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18622 SUBJECT: GRB 151118A, Swift-BAT refined analysis DATE: 15/11/20 00:36:34 GMT FROM: Amy Lien at GSFC C. B. Markwardt (GSFC), A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), 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-239 to T+941 sec from the recent telemetry downlink, we report further analysis of BAT GRB 151118A (trigger #664078) (Amaral-Rogers, et al., GCN Circ. 18611). The BAT ground-calculated position is RA, Dec = 57.169, 65.889 deg which is RA(J2000) = 03h 48m 40.6s Dec(J2000) = +65d 53' 22.0" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 98%. The mask-weighted light curve shows a multi-peaked structure that starts at ~ T0 and ends at ~T+30 s. The structure contains roughly two main pulses that peak at ~ T0 and ~T+7 s, respectively. T90 (15-350 keV) is 23.4 +- 10.5 sec (estimated error including systematics). The time-averaged spectrum from T+0.0 to T+30.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.80 +- 0.20. The fluence in the 15-150 keV band is 4.5 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+6.41 sec in the 15-150 keV band is 1.2 +- 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/664078/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18627 SUBJECT: GRB 151118A: AAO optical upper limit DATE: 15/11/20 15:09:39 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), V. Ayvazian (AAO), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 151118A (Amaral-Rogers et al., GCN 18611) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Nov. 18 (UT) 18:08:09. We do not detect any source within enhanced XRT error circle (Evans et al., GCN 18614): Date UT start t-T0 Filter Exp. UL(3 sigam) (mid, days) (s) 2015-11-18 18:08:09 0.65922 None 35*120 22.1 The photometry is based on nearby USNO-B1.0 stars USNO-B.1_id R2 1559-0079254 15.66 1559-0079234 16.18 1559-0079286 15.60 1559-0079243 16.15 1558-0078596 14.88 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18630 SUBJECT: GRB 151118A: MITSuME Akeno optical upper limits DATE: 15/11/21 08:27:02 GMT FROM: Taketoshi Yoshii at Tokyo Tech Y.Yano, T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 151118A (A. Amaral–Rogers et al., GCN Circular #18611) 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 on 2015-11-18 19:14:09 UT (~16.1 h after the burst). We did not find any new point source within XRT circle in all three bands. We obtained following limits for the magnitudes. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------- 58059 19:44:17 2520 > 20.3 > 19.6 > 18.4 ------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18642 SUBJECT: GRB 151118A iTelescope observation DATE: 15/11/26 10:03:41 GMT FROM: Takanori Sakamoto at AGU Y. Kitaoka, T. Sakamoto, A. Yoshida (AGU) We observed the field of GRB 151118A detected by Swift (trigger #664078; Amaral-Rogers et al., GCN Circ. 18611) with the iTelescope.Net (http://www.itelescope.net) T7 (17" Plane Wave) telescope located at the AstroCamp Observatory (Nerpio, Spain). 20 images of 60 sec exposures were taken in the R filter starting from November 18 03:45:22 (UT) about 38.8 minutes after the trigger and stopped on November 18 04:23:04 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the enhanced X-ray afterglow position (Evans et al., GCN Circ. 18614). The estimated five sigma upper limit of the combined image (total exposure of 1200 sec) is ~18.3 using the USNO-B1 catalog.