{
  "bibcode": "2009GCN..9357....1R",
  "body": "W. Rujopakarn (Steward Observatory), B. E. Schaefer (Louisiana State), and\nE.S. Rykoff (UCSB), report on behalf of the ROTSE collaboration:\n\nROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB\n090515 (Swift trigger 352108; Beardmore et al., GCN 9356), producing\nimages beginning 6.5 s after the GCN notice time. An automated response\ntook the first image at 04:45:27.5 UT, 18.0 s after the burst, under fair\nconditions. We took 10 5-sec and 10 20-sec exposures. These unfiltered\nimages are calibrated 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 16.4-17.8; we set the following specific limits.\n\nstart UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?\n--------------------------------------------------------------------\n04:45:27.5   04:45:32.5         5     16.4           18.0       N\n04:45:27.5   04:46:34.6        67     18.4           18.0       Y",
  "circularId": 9357,
  "createdOn": 1242364111000,
  "email": "wiphu@as.arizona.edu",
  "subject": "GRB 090515: ROTSE-III Optical Limits",
  "submitter": "Wiphu Rujopakarn at U AZ/Steward  <wiphu@as.arizona.edu>",
  "eventId": "GRB 090515"
}