{
  "bibcode": "2007GCN..6512....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 070610 (Pagani et al. GCN 6489) with 50cm MITSuME\ntelescope at Okayama Astrophysical Observatory from UT 12:27 to\nUT 12:41 on Jun 11 2007.\n\nWe coadded 12 CCD frames for each band. Exposure time of each\nframe is 1 minute. We made flux calibration using USNO B1.0\ncatalg. No new source was found at the position of the afterglow\ncandidate reported by A. de Ugarte Postigo (GCN 6501) and the XRT\nsource reported by Pagani et al. (GCN 6490). Three sigma limiting\nmagnitudes of our observation are listed below.\n\n----------------------------------------------------\nband   mid-UT          exp.time      upper limit\ng'     Jun 11 12:34   12 x 1 min.    18.7 mag\nRc     Jun 11 12:34   12 x 1 min.    19.0 mag\nIc     Jun 11 12:34   12 x 1 min.    19.0 mag\n----------------------------------------------------",
  "circularId": 6512,
  "createdOn": 1181632048000,
  "email": "yoshida@oao.nao.ac.jp",
  "subject": "GRB 070610: MITSuME OAO optical upper limit",
  "submitter": "Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>",
  "eventId": "GRB 070610"
}