//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23290 SUBJECT: GRB 181002A: Swift detection of a burst DATE: 18/10/02 11:41:28 GMT FROM: David Palmer at LANL J.D. Gropp (PSU), J. A. Kennea (PSU), K. L. Page (U Leicester) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:26:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 181002A (trigger=865036). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 64.736, +15.233 which is RA(J2000) = 04h 18m 57s Dec(J2000) = +15d 13' 60" 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 30 sec. The peak count rate was ~900 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 11:28:59.2 UT, 136.0 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 64.7464, 15.2136 which is equivalent to: RA(J2000) = 04h 18m 59.13s Dec(J2000) = +15d 12' 48.8" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 78 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 consistent with the Galactic value of 2.79 x 10^21 cm^-2 (Willingale et al. 2013). The initial flux in the 2.5 s image was 7.41e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 144 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 0.60. Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.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/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23292 SUBJECT: GRB 181002A: Enhanced Swift-XRT position DATE: 18/10/02 13:44:29 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 336 s of XRT Photon Counting mode data and 1 UVOT images for GRB 181002A, 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 = 64.74661, +15.21290 which is equivalent to: RA (J2000): 04h 18m 59.19s Dec (J2000): +15d 12' 46.4" with an uncertainty of 2.0 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: 23293 SUBJECT: GRB 181002A: MASTER optical observation DATE: 18/10/02 16:13:52 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, D. Vlasenko, N.Tiurina,V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, Lomonosov Moscow State University,SAI A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) MASTER-Tunka robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located near Baykal lake in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the Swift GRB181002A (Gropp et al. GCN 23290, Beardmore et al. GCN 23292) 03h50min08sec after trigger time at 2018-10-02 2018-10-02 15:16:51 UT. There is no astrophysical optical counterparts inside error-box (ra=04h 18m 59.19s dec=+15d 12' 46.4" r=2.0 arcsec) brighter than 20.3mag. The message may be cited. ==================================================================== Galactic latitude: -23.628772, Galactic longitude: 179.675296 Observations started when Object_Altitude was 17.32 Sun_Altitude: -37.57 Moon_AAltitude: -0.05, Azimuth: 234.39 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23294 SUBJECT: GRB 181002A: Swift-BAT refined analysis DATE: 18/10/02 22:58:09 GMT FROM: Amy Lien at GSFC J. R. Cummings (CPI), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), H. A. Krimm (NSF/USRA), 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-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 181002A (trigger #865036) (Gropp et al., GCN Circ. 23290). The BAT ground-calculated position is RA, Dec = 64.739, 15.248 deg which is RA(J2000) = 04h 18m 57.4s Dec(J2000) = +15d 14' 51.6" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 70%. The mask-weighted light curve shows a weak pulse that starts at ~T-30 s and ends at ~T+45 s. T90 (15-350 keV) is 63.4 +- 12.4 sec (estimated error including systematics). The time-averaged spectrum from T-28.38 to T+43.62 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.15 +- 0.23. The fluence in the 15-150 keV band is 8.8 +- 1.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+11.39 sec in the 15-150 keV band is 0.6 +- 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/865036/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23297 SUBJECT: GRB 181002A: Swift/UVOT Upper Limits DATE: 18/10/03 10:48:04 GMT FROM: Sam Emery at MSSL-UCL S.W.K. Emery (UCL-MSSL) and J. D. Gropp (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 181002A 144 s after the BAT trigger (Gropp et al., GCN Circ. 23290). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 23292) 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 144 294 147 >20.8 u_FC 302 552 246 >20.3 white 144 1008 334 >20.7 v 632 1058 58 >17.9 b 558 751 39 >18.6 u 302 726 265 >20.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.60 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23298 SUBJECT: GRB181002A: GOTO optical limits DATE: 18/10/03 13:34:51 GMT FROM: Danny Steeghs at U.of Warwick/GOTO K.Ulaczyk, D.Steeghs, J.Lyman (U. Warwick), G.Ramsay (Armagh O.), M.Dyer (U. Sheffield), B.Gompertz, A.Levan, R.Cutter (U. Warwick) K. Ackley, D.Galloway, E.Rol (Monash U.), V.Dhillon (U. Sheffield), P.O'Brien, R.Starling (U. Leicester), S.Poshyachinda (NARIT), D.Pollacco (U. Warwick), E.Thrane (Monash U.), E.Palle (IAC) report on behalf of the GOTO collaboration: In response to GRB 181002A (Gropp et al. GCN 23290), the Gravitational-wave Optical Transient Observer (GOTO) observed the field near the Swift BAT/XRT detection. Observations started at 2018-10-03T01:19:02 UT (13.9 hours after the burst) consisting of a set of 3x5x120s exposures in our wide L filter (400-700nm). We do not detect any optical source within the error circle of the enhanced XRT location (Beardmore et al. GCN 23292) with a 5-sigma limit of g=20.8, using PanSTARRS calibrators on the stacked image. We note that our limits are deeper than those reported in Lipunov et al. GCN 23293 and Emery et al. GCN 23297, albeit obtained 13.9 hours post-burst. GOTO is operated at the La Palma observing facilities of the University of Warwick on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT) and the Instituto de Astrofisica de Canarias (IAC) https://goto-observatory.org/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23301 SUBJECT: GRB 181002A: Swift-XRT refined Analysis DATE: 18/10/03 16:36:47 GMT FROM: Kim Page at U.of Leicester J.D. Gropp (PSU) reports on behalf of the Swift-XRT team: We have analysed 935 s of XRT data for GRB 181002A (Gropp et al. GCN Circ. 23290), from 142 s to 1.1 ks after the BAT trigger. The data comprise 95 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. 23292). The light curve can be modelled with a power-law decay with a decay index of alpha=4.15 (+0.18, -0.16). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.60 (+0.18, -0.17). The best-fitting absorption column is 4.0 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of 2.8 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 2.8 x 10^-11 (6.7 x 10^-11) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Total column: 4.0 (+0.7, -0.6) x 10^21 cm^-2 Galactic foreground: 2.8 x 10^21 cm^-2 Excess significance: 3.2 sigma Photon index: 2.60 (+0.18, -0.17) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00865036. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23308 SUBJECT: GRB 181002A: Mondy optical upper limit DATE: 18/10/05 07:28:44 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova (IKI) report on behalf of of larger GRB follow-up collaboration: We observed the field of the GRB 181002A (Gropp et al., GCN 23290) with AZT-33IK telescope of Sayan observatory (Mondy). We obtained several images in R-filter starting on Oct. 02 (UT) 16:31:56. We do not detect any object within enhanced Swift-XRT position (Beardmore et al., GCN 23292). Preliminary photometry of the field is following. Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2018-10-02 16:31:56 0.23281 R 58*60 n/d n/d 22.9 The photometry is based on nearby SDSS-DR12 stars SDSS-DR12_id R(Lupton) J041903.61+151252.8 18.69 J041903.16+151309.7 18.40 J041848.32+151242.2 16.52 J041904.57+151201.2 17.35 J041857.89+151107.8 17.14