{
  "bibcode": "2005GCN..3190....1S",
  "body": "GRB 050408: ROTSE-III Optical Limits\n\nD.A. Smith, S.A. Yost, & E.S. Rykoff (U of Michigan) report on behalf of the\nROTSE collaboration:\n\nROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB\n050408 (HETE trigger 3711).  An automated response produced images beginning at\n16:23:09.4 UT, 18.5 s after the trigger time and 6.6 s after the alert was\ndistributed.  The first few images were therefore recorded while the burst was\nstill active at high energies (Sakamoto et al., GCN Circ. #3189).  The\ntelescope took 10 5-sec, 10 20-sec, and a series of 60-sec eposures. These\nunfiltered images are calibrated relative to USNO A2.0 (R). The ROTSE-III\nimages show strong and increasing degredation from clouds.  After the 20th\nimage (~7.7 min after the trigger time), clouds became opaque enough to render\nmany images useless.\n\nComparison to the DSS (second epoch) reveals no new sources within the 3-sigma\nSXC error circle. Individual images have limiting magnitudes ranging from\n14.7-16.9. In particular, we set a limit of magnitude 14.7 in the first 5 s\nexposure. Coadding the first ten images yields a limiting magnitude of 15.1,\nand coadding the 20-s images (165.5-522.5 s after the trigger time) yields a\nlimiting magnitude of 17.8.",
  "circularId": 3190,
  "createdOn": 1112986412000,
  "email": "dasmith@rotse2.physics.lsa.umich.edu",
  "subject": "GRB 050408: ROTSE-III Optical Limits",
  "submitter": "Don Smith at U michigan  <dasmith@rotse2.physics.lsa.umich.edu>",
  "eventId": "GRB 050408"
}