{
  "bibcode": "2009GCN..9201....1C",
  "body": "S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration:\n\nWe have imaged the field of GRB090423 (GCN 9198, Krimm et al.) with the\nautomated Palomar 60-inch telescope beginning at 2009 23 April 7:58 UT (~\n3 minutes after the burst) in the Sloan r', i', and z' filters.  In\ncoadded images we find no sources inside the XRT error circle to the\nfollowing limiting magnitudes (calculated with respect to several SDSS\nstars in the field):\n\nMean UT\t\tt_b (min)\tFilter\t\tMagnitude\n---------------------------------------------------------------------\n23 Apr 08:11\t16\t\tr'\t\t> 21.5\n23 Apr 08:15\t20\t\ti'\t\t> 21.5\n23 Apr 08:17\t22\t\tz'\t\t> 20.5\n\nThe lack of an optical afterglow, together with the fact that the X-ray\ncolumn density is consistent with the Galactic value (Krimm et al., GCN\n9198), make GRB090423 an interesting candidate high-redshift event.  We\nencourage observations at longer wavelengths to search for a NIR\ncounterpart.",
  "circularId": 9201,
  "createdOn": 1240479980000,
  "email": "cenko@srl.caltech.edu",
  "subject": "GRB 090423: P60 Observations",
  "submitter": "S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>",
  "eventId": "GRB 090423"
}