Gamma-ray Burst 011019

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN notice #1109
  G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team;
  N. Butler, R. Vanderspek, G. Crew, J. Doty, G. Monnelly, J. Villasenor, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
  N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, T. Donaghy, and C. Graziani, on behalf of the HETE WXM Team;
  J-L Atteia, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE FREGATE Team;
  write:
  The HETE Fregate and WXM instruments detected and localized a faint burst at 31370 SOD {08:42:50} UT on 19 October. The burst was an untriggered event, and appears to be an X-ray rich GRB with a duration of ~30 seconds.
  In the Fregate 8-40 keV band, the statistical significance was 8.2 sigma. A total of 998 counts were detected during that interval, corresponding to a fluence of ~1.8 x 10-7 ergs cm-2 . The peak flux was ~3.4 x 10-8 ergs cm-2 s-1 (ie ~1 x Crab flux). In the WXM 2-10 keV band, the statistical significance was 8.4 sigma.
  Based on the WXM data, the best fit location for GRB011019 is:

    R.A.(2000) = 00h42m50s.23, Dec.(2000) = -12o26'58"
  

  The 1-sigma (68.3%) uncertainty radius for this localization is 21 arcminutes (7.5' statistical error combined in quadrature with 19.8' systematic error). The 2-sigma (95.5%) uncertainty radius is 35 arcminutes.
  Although the HETE spacecraft was approaching the nighttime part of its orbit, and HETE's field of view was clear of the earth, the sunlit part of the earth was close to the star camera field of view. The star cameras could not track stars because of the scattered light. Thus the spacecraft attitude was estimated using data from the fine sun sensor and magnetometers rather than the star cameras. For this condition, the errors in the attitude solution are larger than if the star cameras are used. As a result, the estimated error in the attitude solution is unusually large.
• GCN notice #1110
  A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
  We have acquired single V-band images with the NOFS 1.0m telescope from 011020 0537-0703 UT, forming a mosaic that covers the central 32x32arcmin of the HETE error box (GCN 1109). Our images go somewhat fainter than the DPOSS limit.
  We find no new source down to the DPOSS limit within our field. There is one bright asteroid about 9arcmin NW of the field center, near a pair of bright stars, moving towards the east.
• GCN notice #1111
  There is a small mistake in GCN 1110. The asteroid is moving to the *west* at about 0.5arcsec/minute.
• GCN notice #1112
  P.A. Price, B.P. Schmidt, T.S. Axelrod (RSAA, ANU) and D.W. Fox (Caltech) report:
  We have observed the centre 40 arcmin square region of the error box of GRB 011019 (GCN #1109) with the robotic 50-inch telescope at Mount Stromlo Observatory, commencing at 2001 Oct 20.39 UT. Our combined 3x300 sec images in MACHO R band have a limiting magnitude of approximately R ~ 19.5 mag. Neither automated or manual comparison of the images with the Digital Sky Survey reveal the presence of an optical transient. Further observations are planned.
• GCN notice #1115
  Carl Akerlof, Timothy McKay, Eli Rykoff, and Donald Smith on behalf of the ROTSE collaboration
  The ROTSE-III 0.45-m telescope located at Los Alamos National Laboratory responded to the announcement of GRB011019 (GCN 1109) at 2:20 UT, 20-Oct-2001, 17.6 hours after the burst was detected by HETE-2. Twenty 60-second exposures were obtained followed by additional images at 05:49 UT on 20-Oct-2001 and at 02:16 UT on 21-Oct-2001. With a threshold detection level of m_R ~ 19, no fading transients were discovered within the 35' two sigma error circle. Two asteroids within the error box were identified by their proper motion.
• GCN notice #1116
  D. W. Fox (Caltech) and P. A. Price (MSO/ANU), with S. Pravdo, E. Helin, K. Lawrence, and M. Hicks of the NEAT/Palomar team, report on behalf of the Caltech-NRAO-CARA GRB collaboration:
  We have observed the 35 arcmin-radius error circle of GRB011019 with the 48-inch NEAT automated telescope on Mt. Palomar. In 1.13-degree by 1.13-degree images taken on 21 October 05:00 UT and 05:31 UT we cover almost the full error circle to limiting magnitudes deeper than the Digitized Sky Survey (DSS). Visual comparison of the images with the DSS reveals a single asteroid but no other obvious new objects, to a limiting magnitude of roughly R~19.5.
• GCN notice #1128
  Y. Komiyama, on behalf of the SuprimeCam Team:
  G. Kosugi, N. Kobayashi, Y. Mizumoto, M. Iye, R.Ogasawara T. Takata, K. Sekiguchi, T. Yamada, J. Watanabe, and T. Totani, on behalf of the Subaru GRB Team:
  We have obtained several R-band images with the Subaru 8.2m telescope atop Mauna Kea on 2001 October 20 beginning at 10:14 (25.5 hours after the burst), 10:19, 12:21, and 12:26 UT to search fading objects. The observing instrument was Suprime-Cam and the central 34 x 50 arcmin of the HETE error box (GCN 1109) was covered by two consecutive pointings with the exposure time of 180 seconds each. Due to the heavy cirrus coverage the limitting magnitude was R = 22.5 (+/- 0.2 mag of photometric measurement error at the magnitude) for the first exposures and R = 25.0 (+/- 0.2) for the second exposures.
  We find no new object down to the DSS-2 limit within our field and no fading object with the variability grater than 3 sigma threshould of the photometric error in 2 hours.
• GCN notice #1130
  S. Bondar (Kosmoten), A. Pozanenko (IKI), V. Rumyantsev (CrAO), G. Beskin (SAO)
  We have observed the 35 arcmin-radius error circle of GRB 011019 (GCN 1109) with 600mm automated telescope (TT600) of Kosmoten observatory. Two images were taken in at 22:00 UT on 19-Oct-2001 (13.3 hours after burst trigger) and 00:01 UT on 20-Oct-2001. Limiting magnitude of first image was approximately R ~ 15.5. Visual comparison with DSS reveals no optical transients in both images.