{
  "bibcode": "2007GCN..7026....1I",
  "body": "T. Ishimura, Y. Yatsu, T. Shimokawabe, N. Kawai (Tokyo Tech) and\nM. Yoshida (NAOJ) report on behalf of the MITSuME collaboration:\n\nWe observed the field of GRB 071020 (Holland et al. , GCN6949) with\nthe 3-color 50cm MITSuME Telescope at Akeno, Japan from UT 16:21 to\nUT 19:53 on Oct. 20, 9.3 hours after the trigger.\n\nIn the co-added images of Ic and Rc bands, we detected the optical\nafterglow reported by Schaefer et al. (GCN 6948).  Photometric\ncalibration was done using the USNO-B1.0 (Ic-band) and NOMAD (g'- and\nRc-bands) catalogs.  The results are following:\n\nFilter  start     end         Exposure      Mag\n------------------------------------------------------\ng'     16:21:13  19:53:55    149 x 60s  >21.1  (3 sigma upper limit)\nRc     16:21:13  19:53:55    149 x 60s  21.2 +/- 0.3\nIc     16:21:13  19:53:55    149 x 60s  19.8 +/- 0.3\n------------------------------------------------------",
  "circularId": 7026,
  "createdOn": 1193830694000,
  "email": "nkawai@hp.phys.titech.ac.jp",
  "subject": "GRB 071020: MITSuME Akeno optical observations",
  "submitter": "Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>",
  "eventId": "GRB 071020"
}