{
  "bibcode": "2007GCN..6975....1Y",
  "body": "M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama, H. Toda\n(NAOJ), and N. Kawai (Tokyo Tech) report on behalf of the\nMITSuME collaboration:\n\nWe observed the field of GRB071021 (Sakamoto et al., GCN6958)\nwith the three-color 50cm MITSuME Telescope at Okayama\nAstrophysical Observatory. The observations started at 9:45:30\nOct. 21 UT (3m58s after the trigger). No new point source was\nfound in the XRT error circle of this burst (Barbier et al.,\nGCN6966). The 3-sigma upper limits derived with the USNO B1.0\ncatalog are followings.\n\n-------------------------------------------------------------\n      Mid time            Exp time        G     Rc     Ic\n-------------------------------------------------------------\n2007-10-21  9:57:03   20min (60s x 20)  >19.4  >19.1  >18.7\n2007-10-21 10:48:01   99min (60s x 99)  >20.3  >19.6  >19.3\n-------------------------------------------------------------",
  "circularId": 6975,
  "createdOn": 1193033015000,
  "email": "yoshida@oao.nao.ac.jp",
  "subject": "GRB071021: MITSuME Okayama Optical Upper Limits",
  "submitter": "Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>",
  "eventId": "GRB 071021"
}