{
  "bibcode": "2003GCN..2240....1L",
  "body": "Andrew Levan (U. Leicester/STScI), Andrew Fruchter (STScI), Johan Fynbo\n(U. Aarhus), Paul Vreeswijk (ESO) and Javier Gorosabel (IAA-CSIC/STScI)\nreport for the GOSH collaboration.\n\nThe field of GRB 021004 has been observed using the ACS/WFC on HST\nin four epochs: the 7th, 11th and 22nd Oct and 26th Nov 2002.\n\nA difference image of the last two epochs, which were dithered, reveals a\ndeclining point source whose position is consistent within the astrometric\nerrors (~0.\"01) with the peak of the light in the later image.  The source\nis marginally resolved in that image (with a FWHM of 0\".11, compared to a\npoint source FWHM of ~0.\"09) indicating a host galaxy directly underlying\nthe OT. This differs from the astrometry of Mirabal et al\n(astro-ph/0303616) who find the OT position well offset from the host. As\nthe source lies on the peak of the light, and the object is only\nmarginally resolved, it is possible that the OT continues to contribute\nsignificantly to the observed brightness even at the later epoch. Hence\nthe magnitude found for the source in November, F606W(AB)=24.3 +/- 0.1,\nis an upper limit on the true brightness of the host galaxy.\n\nWe have scheduled late time observations of GRB 021004 which will enable\nan accurate determination of both the host galaxy magnitude and the late\ntime decay of the afterglow.\n\nImages of the field can be found at\n\nhttp://www.stsci.edu/~fruchter/GRB/021004",
  "circularId": 2240,
  "createdOn": 1053517068000,
  "email": "anl@star.le.ac.uk",
  "subject": "GRB 021004: HST observations",
  "submitter": "Andrew Levan at U.of Leicester  <anl@star.le.ac.uk>",
  "eventId": "GRB 021004"
}