{
  "bibcode": "2015GCN.18171....1F",
  "body": "T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, Y. Yano,\nS. Kurita, Y.Ono, S.Harita,Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)\nreport on behalf of the MITSuME collaboration:\n\nWe searched for the optical counterpart of GRB 150818A (V. D'Elia et al. GCN Circular #18152) with the\noptical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.\n\nThe observation started on 2015-08-18 11:54:53 UT (~18 min after the burst).\nWe did not find any new point source within XRT circle in all three bands.\n\nWe obtained following limits for the magnitudes.\n\nT0+[sec]      MID-UT      T-EXP[sec]         g'           Rc           Ic\n---------------------------------------------------------------------------------------\n  1101     11:59:46          540           >19.4      >19.4     > 18.5\n---------------------------------------------------------------------------------------\nT0+ : Elapsed time after the burst\nT-EXP: Total Exposure time\nWe used GSC2.3 catalog for flux calibration",
  "circularId": 18171,
  "createdOn": 1439987935000,
  "email": "yoshii.t.ac@m.titech.ac.jp",
  "subject": "GRB 150818A: MITSuME Akeno optical upper limits",
  "submitter": "Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>",
  "eventId": "GRB 150818A"
}