{
  "bibcode": "2013GCN.14454....1Y",
  "body": "Y. Yatsu, Y. Yano,  R. Usui, Y. Tachibana, K. Ito, T. Yoshii,\nS. Kurita, Y. Saito, and N. Kawai (Tokyo Tech)\nreport on behalf of the MITSuME collaboration:\n\nWe observed GRB 130427A (Maselli et al., GCNC 14448) with an\noptical tri-color (g, Rc, and Ic)  camera attached to the MITSuME\n50 cm telescope of Akeno Observatory, Yamanashi, Japan.\n\nThe observation started on 2013-04-27 10:06:09.60 UT (8293 sec after the\ntrigger).\nAnd we found the optical counterpart reported in the twilight sky.\nThe measured magnitudes were listed below.\n\nMID-MJD  T-EXP[sec]         g'                 Rc                Ic\n-------------------------------------------------------------------------------------------\n 56409.4231929  360  15.66+/-0.10  15.03+/-0.07  14.71+/-0.09\n-------------------------------------------------------------------------------------------\nT-EXP: Total Exposure time [sec]\n(The photon flux were calibrated against GSC2.3 catalog.)",
  "circularId": 14454,
  "createdOn": 1367061558000,
  "email": "yatsu@hp.phys.titech.ac.jp",
  "subject": "GRB 130427A: MITSuME Akeno Optical observation(T0+8000s~)",
  "submitter": "Yoichi Yatsu at Tokyo Tech.  <yatsu@hp.phys.titech.ac.jp>",
  "eventId": "GRB 130427A"
}