{
  "bibcode": "2013GCN.15143....1Y",
  "body": "T. Yoshii, K. Ito, Y. Saito, Y. Yano, R. Usui, Y. Tachibana, \nS. Kurita, Y. Yatsu, and N. Kawai (Tokyo Tech)\nreport on behalf of the MITSuME collaboration:\n\nWe observed the field of GRB 130831A (L. M. Z. Hagen et al., GCNC 15139) with the \noptical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME 50 cm\ntelescope of Akeno Observatory, Yamanashi, Japan.\nAnd we continue observing .\n\nThe observation started on 2013-08-31 13:06:14 UT ( 118 sec after the burst).\nAnd we detected the previously reported afterglow .\nBut weather condition was not so good.\nThe measured magnitudes were listed below.\n\nT0+[sec]       MID-UT        T-EXP[sec]              g'                            Rc                          Ic \n------------------------------------------------------------------------------------------------------------------------------\n  ~118           13:07:41         300              15.40+/-0.23        15.16+/-0.33            analyzing\n------------------------------------------------------------------------------------------------------------------------------\n(The photon flux were calibrated against GSC2.3 catalog.)",
  "circularId": 15143,
  "createdOn": 1377961391000,
  "email": "yoshii.t.ac@m.titech.ac.jp",
  "subject": "GRB 130831A: MITSuME Akeno Optical observation",
  "submitter": "Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>",
  "eventId": "GRB 130831A"
}