{
  "bibcode": "2007GCN..6356....1R",
  "body": "E.S. Rykoff (U Mich), B. E. Schaefer (Louisiana State), H. Swan (U \nMich), report on behalf of the ROTSE collaboration:\n\nROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, \nresponded to GRB 070429 (Swift trigger 277571, GCN 6355, Barthelmy, et \nal), producing images beginning 6.7 s after the GCN notice time. An \nautomated response took the first image at 01:36:46.7 UT, 96.6 s after \nthe burst, under good conditions. We took 10 5-sec, 10 20-sec exposures; \nimaging is ongoing. These unfiltered images are calibrated relative to \nUSNO A2.0 (R).\n\nComparison to the DSS (second epoch) reveals no new sources within the \n3-sigma BAT error circle or the XRT error circle, for both single images \nand coadding into sets of 10; however, we are limited as the field is \nsomewhat crowded. Individual images have limiting magnitudes ranging \nfrom 16.1-17.1; we set the following specific limits.\n\nstart UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?\n--------------------------------------------------------------------\n01:36:46.7   01:36:51.7         5     16.2           96.6       N\n01:36:46.7   01:38:04.4        77     17.3           96.6       Y\n01:38:19.4   01:43:08.1       288     18.0          189.3       Y",
  "circularId": 6356,
  "createdOn": 1177811827000,
  "email": "erykoff@umich.edu",
  "subject": "GRB 070429: ROTSE-III Optical Limits",
  "submitter": "Eli Rykoff at U of Michigan/ROTSE  <erykoff@umich.edu>",
  "eventId": "GRB 070429"
}