{
  "bibcode": "2002GCN..1514....1G",
  "body": "Mike Gladders (Carnegie Observatories) and Pat Hall\n(Princeton/Catolica) report: \n\n\"The photometric data reported previously by us yield the following\ndecay slopes for the OT of GRB020813.  The decay slopes in various\nfilters implied by the data from August 13UT are:\n\n    I: -0.677+-0.016 (all data August 13UT)\n    I: -0.76+-0.03 (only UT>6.5, to match R&V time range)\n    R: -0.82+-0.06\n    V: -0.75+-0.05\n\n\"These data are consistent with the same power law decay in all three\nfilters in the time interval 6.5<UT<7.5, and are consistent with the\ndiscussion in GCN #1476. Based purely on these data, the two earlier\nI-band data points are 0.045+-0.015 magnitudes too faint, implying\nthat a break in the decay has already occurred by ~4 hours after the\nGRB event. This is again consistent with GCN #1476.\n\n\"Also, the data yield decay slopes between August 13 and 14 UT of\n-0.96+-0.04,-1.02+-0.01,-1.01+-0.02 in I,R and V respectively. These\nvalues lie midway between the early time slope (above, and GCN #1476),\nand the later time slope of -1.4+-0.02 (August 13.99 UT to August\n16.03 UT, GCN #1500). The slope derived here is nominally inconsistent\nwith the decay reported in GCN #1491 (-1.44) over a time window\nsimilar to the data reported here.  However, allowing for the\nuncertainties of the three data points in GCN #1491 yields a decay\nslope of -1.3+-0.30, consistent with the results reported here.\n\n\"It thus appears that the decay slope of this OT has continued to\nsteepen with time, rather than having undergone a simple break.\"",
  "circularId": 1514,
  "createdOn": 1029899971000,
  "email": "derekfox@astro.caltech.edu",
  "subject": "GRB020813: VRI Decay Slopes",
  "submitter": "Derek Fox at CIT  <derekfox@astro.caltech.edu>",
  "eventId": "GRB 020813"
}