{
  "bibcode": "2019GCN.25854....1A",
  "body": "R. Adachi, K. L. Murata, M. Oeda, K.Shiraishi, K. Iida, M. Niwano,\nF. Ogawa, R. Hosokawa, S. Toma, Y. Yatsu, and N. Kawai (TokyoTech)\nreport on behalf of the MITSuME collaboration:\n\nWe searched for the optical counterpart of GRB 190926A (A. Melandri et\nal., GCN Circular #25848) 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 16:16:33 UT. We did not find any new point\nsources within the XRT circle (M.R. Goad et al., GCN Circular #25850)\nin all three bands.\nWe obtained the following 5-sigma limits for the magnitudes.\n\nT0+[hour]   MID-UT    T-EXP[sec]    5-sigma limits\n------------------------------------------------------------------------------------------------\n ~7.0         18:13:34    6960              g'>19.8, Rc>19.5, Ic>19.2\n------------------------------------------------------------------------------------------------\nT0+ : Elapsed time after the burst\nT-EXP: Total Exposure time\nWe used UCAC4 catalog for flux calibration.\nThe magnitudes are expressed in the AB system.",
  "circularId": 25854,
  "createdOn": 1569555195000,
  "email": "adachi@hp.phys.titech.ac.jp",
  "subject": "GRB 190926A: MITSuME Akeno optical upper limits",
  "submitter": "Adachi Ryo at Tokyo Institute of Tech  <adachi@hp.phys.titech.ac.jp>",
  "eventId": "GRB 190926A"
}