{
  "bibcode": "2009GCN..8807....1S",
  "body": "H. Swan (U Mich), E.S. Rykoff (UCSB), T. Guver (U Arizona), T.A. McKay \n(U Mich), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), R. Quimby \n(Caltech), report on behalf of the ROTSE collaboration:\n\nROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe, \nTurkey, responded to GRB 090113 (Swift trigger 339852; H. A. Krimm, GCN \n8804), producing images beginning 6.4 s after the GCN notice time. An \nautomated response took the first image at 18:49:02.4 UT, 503.2 s after \nthe burst, under windy conditions. We took 10 5-sec, 10 20-sec and 30 \n60-sec exposures. These unfiltered images are calibrated relative to \nUSNO 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, for both single images and coadding into \nsets of 10; the field is not crowded. Individual images have limiting \nmagnitudes ranging from 14.9-16.4; we set the following specific limits.\n\nstart UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?\n--------------------------------------------------------------------\n18:49:02.5   18:51:08.2       125     16.6          503.3       Y\n18:51:16.6   18:55:52.3       275     17.3          637.4       Y\n18:60:45.7   19:05:21.5       275     17.3         1206.5       Y",
  "circularId": 8807,
  "createdOn": 1231889029000,
  "email": "hflewell@umich.edu",
  "subject": "GRB 090113: ROTSE-III Optical Limits",
  "submitter": "Heather Swan at U.of Michigan/ROTSE  <hflewell@umich.edu>",
  "eventId": "GRB 090113"
}