{
  "bibcode": "2008GCN..7349....1S",
  "body": "B. E. Schaefer (Louisiana State) and W. Rujopakarn (Steward), report on \nbehalf of the ROTSE collaboration:\n\nROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to \nGRB 080303A (Swift trigger 304549), producing images beginning 8.4 s after \nthe GCN notice time. An automated response took the first image at \n09:10:55.3 UT, 20.0 s after the burst, and during the gamma-ray emission, \nunder twilight conditions. We took 10 5-sec, 10 20-sec and 10 60-sec \nexposures. These unfiltered images are calibrated relative to USNO A2.0 \n(R). Imaging is on going.\n\nComparison to the DSS (second epoch) reveals no new sources within the \n3-sigma Swift/BAT error circle or the XRT error circle, for both single \nimages and coadding into sets of 10; the field is not crowded. Individual \nimages have limiting magnitudes ranging from 13.3-15.8, with the poor \nlimits at the start due to the bright twilight that was rapidly fading.  \nWe set the following specific limits.\n\nstart UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?\n--------------------------------------------------------------------\n09:10:55.4   09:11:00.4         5     13.3           20.1       N\n09:10:55.4   09:13:06.9       131     14.1           20.1       Y\n09:21:35.1   09:29:30.1       475     16.2          659.8       Y",
  "circularId": 7349,
  "createdOn": 1204537093000,
  "email": "schaefer@grb.phys.lsu.edu",
  "subject": "GRB 080303A: ROTSE-III Optical Limits",
  "submitter": "Brad Schaefer at LSU  <schaefer@grb.phys.lsu.edu>",
  "eventId": "GRB 080303A"
}