{
  "bibcode": "2004GCN..2899....1R",
  "body": "E. Rykoff (U. Michigan) reports on behalf of the ROTSE collaboration:\n\nROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, \nresponded to Swift GRB041223 (GCN #2898).  A manual response was \ninitiated at 18:27 UT, around 4.5 hours after the burst.  We took 10 5-s \nexposures followed by 200 20-s exposures.  The first images were taken \nduring twilight, and all the images were taken with >90% moon \nillumination.  The unfiltered images were calibrated relative to USNO \nA2.0.  Individual images had limiting magnitudes around 16.8. Comparison \nto DSS (second epoch) reveals no new sources within the 3-sigma error \ncircle to a limiting magnitude of 18.4 for a stack of the first 90 images.",
  "circularId": 2899,
  "createdOn": 1103832524000,
  "email": "erykoff@umich.edu",
  "subject": "GRB041223: ROTSE-III Optical Observations",
  "submitter": "Eli Rykoff at Univ. of Michigan/ROTSE  <erykoff@umich.edu>",
  "eventId": "GRB 041223"
}