{
  "bibcode": "2020GCN.27576....1O",
  "body": "F. Ogawa, R. Adachi, R. Hosokawa, K. L. Murata, M. Niwano, N.\nNakamura, Y. Yatsu, and N. Kawai(TokyoTech) report on behalf of the\nMITSuME collaboration:\n\nWe searched for the optical counterpart of GRB 200412B (The Fermi GBM\nteam, GCN Circular #27547) with the optical three color (g', Rc, and\nIc) CCD cameras attached to the MITSuME 50 cm telescope of Akeno\nObservatory, Yamanashi, Japan.\nThe observation started on 2020-04-13 15:27:09 UT. We detected the\npoint source at the position consistent with the afterglow detected\npreviously (E. Gorbovskoy et al. GCN #27555).\nWe measured the magnitudes as follows.\nT0+[hour] MID-UT T-EXP[sec] measured magnitudes\n------------------------------------------------------------------------------------------------\n30.2 2020-04-13 17:19:02 10800 g'=20.1+/-0.2,Rc=19.6+/-0.2,Ic=19.5+/-0.2\n------------------------------------------------------------------------------------------------\nT0+ : Elapsed time after the burst\nT-EXP: Total Exposure time\nWe used GSC2.3 catalog for flux calibration.\nThe magnitudes are expressed in the Vega system.",
  "circularId": 27576,
  "createdOn": 1586865160000,
  "email": "ogawa@hp.phys.titech.ac.jp",
  "subject": "GRB 200412B: MITSuME Akeno optical observation",
  "submitter": "Ogawa Futa at Tokyo Institute of Technology  <ogawa@hp.phys.titech.ac.jp>",
  "eventId": "GRB 200412B"
}