{
  "bibcode": "2004GCN..2539....1P",
  "body": "H. Pedersen, Copenhagen University Observatory, on behalf of the GRACE team,\nreports:\n\n\"The Descartes Optical Telescope, consisting of a parallactically mounted\nF=24 mm, f/2.8 lens and a 1472 x 2184 pixel CCD (pixel size: 6.8 micron),\nis currently undergoing tests at ESO, La Silla, during which serendipitous\nobservations of the GRB040228 error box (Nakagawa et al. GCN 2536, see\nalso Hurley et al. GCN 2538) were done on several nights starting February\n22 d 1 h UTC. No filter was used, and all exposures lasted 30 s followed\nby 30 s read-out. During each of the first five nights integrations\nspanning several hours were obtained under mostly good conditions.\nNo observations were attempted on February 27. On the night of trigger \nno. H3066 a partial clearing started more than an hour later. A set of 24 \nexposures obtained in the time interval from 75 to 99 minutes after the \ntrigger are of fairly uniform quality and have been co-added. No candidate \nafterglow is seen in or near the error box to m(r) = 10.2, based on USNO \nphotometry of U0825_07125568, a star near the centre of the error box. \nObservations taken in the time interval from 46 to 45 hours prior to the \nGRB likewise give no indication of 'preglow', to a limit of m(r) = 10.5.\n\nAll values are preliminary and should not be published before further\nconfirmation.\"",
  "circularId": 2539,
  "createdOn": 1078254733000,
  "email": "holger@astro.ku.dk",
  "subject": "GRB 040228 Optical observations",
  "submitter": "Holger Pedersen at Copenhagen U Obs  <holger@astro.ku.dk>",
  "eventId": "GRB 040228"
}