{
  "bibcode": "2007GCN..6552....1Y",
  "body": "M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ)\nand N. Kawai (Tokyo Tech) report on behalf of the MITSuME\ncollaboration:\n\nWe performed optical imaging observation (g', Rc, and Ic) of the\nfield of GRB 070616 (Starling et al. GCN 6542) with 50cm MITSuME\ntelescope at Okayama Astrophysical Observatory from UT 18:04:40\n(1h 35m after burst) to UT 18:10:30 on June 16 2007.\n\nWe coadded 5 CCD frames for each band. Exposure time of each\nframe is 1 minute. We made flux calibration using USNO B1.0\ncatalg. We could not identify new source at the position of the\nafterglow candidate reported by Fatkhullin et al. (GCN 6547) and\nUgarte Postigo (GCN 6548). Three sigma limiting magnitudes of\nour observation are listed below.\n\n----------------------------------------------------\nband  mid-UT (2007)      exp.time     upper limit\ng'    June 16 18:07:35   5 x 1 min.   19.5 mag\nRc    June 16 18:07:35   5 x 1 min.   18.9 mag\nIc    June 16 18:07:35   5 x 1 min.   18.4 mag\n----------------------------------------------------",
  "circularId": 6552,
  "createdOn": 1182143126000,
  "email": "yoshida@oao.nao.ac.jp",
  "subject": "GRB070616: Optical Observation by MITSuME Okayama",
  "submitter": "Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>",
  "eventId": "GRB 070616"
}