{
  "bibcode": "2018GCN.22670....1H",
  "body": "T. Horiuchi,  H. Hanayama, M. Honma (IAO, NAOJ),\nR. Itoh, K. Shiraishi, K. Murata, Y. Tachibana and  N. Kawai (Tokyo Tech)\nreport on behalf of the MITSuME and OISTER collaboration:\n\nWe observed the field of GRB 180418A (D'Elia et al.,GCN 22646)\nwith the optical three color (g', Rc and Ic) CCD camera attached\nto the Murikabushi 1m telescope of Ishigakijima Astronomical\nObservatory.\n\nThe observation started on 2018-04-18 13:55:32 UT, (~7 hours after\nthe burst). We detected the previously reported afterglow\n(W. Zheng and A. Filippenko, GCNC22647) in the R band.\n\nThe photometric results of the OT are listed below.\nWe used UCAC-4 catalog for flux calibration.\n\n#T0+[hour]  MID-UT    T-EXP[sec] g'   Rc   Ic\n-------------------------------------------------------------------\n8.6    15:22:01      10380  >22.8  22.4+/-0.5 >22.0\n-------------------------------------------------------------------\nT0+ : Elapsed time after the burst [hour]\nT-EXP: Total Exposure time [sec]",
  "circularId": 22670,
  "createdOn": 1524535228000,
  "email": "itoh@hp.phys.titech.ac.jp",
  "subject": "GRB 180418A: MITSuME Ishigakijima Optical Observation",
  "submitter": "Ryosuke Itoh at Tokyo Institute of Tech.  <itoh@hp.phys.titech.ac.jp>",
  "eventId": "GRB 180418A"
}