{
  "bibcode": "2002GCN..1776....1S",
  "body": "J. Schaefer, S. Savage, R. Canterna (U. Wyoming), M. Nysewander, D.\nReichart (U. North Carolina), A. Henden (USRA/USNO), and D. Lamb (U.\nChicago) report on behalf of a larger collaboration:\n\nWe observed the inner 93% of the 40-arcminute diameter error circle of GRB\n021112 (GCN 1682) with the 0.6-meter Red Buttes Observatory telescope\nbeginning 1.8 hours (GCN 1685) and 13.9 days after the burst.  For the\nfirst epoch observation, we integrated without filter for 1800 seconds per\npointing x four pointings.  For the second epoch observation, we integrated\nwithout filter for 2700 seconds per pointing x four pointings.\n\nUnfiltered magnitudes measured with our Apogee AP8P CCD best mimic Rc\nmagnitudes.  Using the image subtraction routine ISIS2 (Alard 2000), we\nfind no candidates to the limiting magnitude of our first epoch image,\nwhich we measure to be Rc = 21.8 mag (3 sigma), 22.2 mag (2 sigma), and\n23.0 mag (1 sigma) using the field calibration of Henden (GCN 1697).\n\nWe note that the Galactic extinction along this line of sight is\napproximately A_Rc = 0.52 mag (Schlegel et al. 1998).\n\nThe candidate of Strolger et al. (GCNs 1684, 1696) sits outside of the\nabove fields.  In addition to the arguments presented by Nysewander et al.\n(GCN 1701), its BVRcIcH spectral flux distribution and low Galactic\nlatitude suggest that it is a low-mass flare star.\n\nDismissing this candidate, this is the deepest non-detection of an optical\nafterglow beginning within 2.6 hours of a burst (GCN 1699).\n\nAlard, C. 2000, A&AS 114, 363\nSchlegel, D., et al. 1998, ApJ, 500, 525",
  "circularId": 1776,
  "createdOn": 1040516218000,
  "email": "mnysewan@astro.unc.edu",
  "subject": "GRB 021112: Evidence for Another Dark Optical Afterglow",
  "submitter": "Melissa Nysewander at UNC,Chapel Hill  <mnysewan@astro.unc.edu>",
  "eventId": "GRB 021112"
}