{
  "bibcode": "2008GCN..7472....1Y",
  "body": "F. Yuan (U Mich), E.S. Rykoff (UCSB), W. Rujopakarn (Steward), report on \nbehalf of the ROTSE collaboration:\n\nROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB \n080320 (Swift trigger 306858), producing images beginning 6.5 s after \nthe GCN notice time. An automated response took the first image at \n04:38:10.5 UT, 32.1 s after the burst, under fair conditions. We took 10 \n5-sec, 10 20-sec and 20 60-sec exposures. These unfiltered images are \ncalibrated relative to USNO A2.0 (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. Individual images have limiting \nmagnitudes ranging from 16.4-17.5; we set the following specific limits.\n\nstart UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?\n--------------------------------------------------------------------\n04:38:10.5   04:38:15.5         5     16.5           32.1       N\n04:38:10.4   04:39:17.5        67     18.1           32.0       Y",
  "circularId": 7472,
  "createdOn": 1205989311000,
  "email": "yuanfang@umich.edu",
  "subject": "GRB 080320: ROTSE-III Optical Limits",
  "submitter": "Fang Yuan at ROTSE  <yuanfang@umich.edu>",
  "eventId": "GRB 080320"
}