{
  "bibcode": "2019GCN.23649....1O",
  "body": "M. Oeda, R. Adachi, K. L. Murata, R. Itoh, Y. Tachibana, S. Harita, K.\nMorita, K.Shiraishi, K. Iida, M. Niwano,  Y. Yatsu, and N. Kawai (TokyoTech)\nreport on behalf of the MITSuME collaboration:\n\nWe searched for the optical counterpart of GRB 190109A (M. J. Moss  et\nal.,GCN Circular #23642) with the optical three color (g', Rc, and Ic)\nCCD cameras attached to the MITSuME 50 cm telescope of Akeno\nObservatory,Yamanashi, Japan.\n\nThe observation started on 08:18:30.05 UT. We did not find any new\npoint source within the enhanced XRT circle (P.A. Evans et al., GCN\nCircular #23643) in all three bands. We obtained following 3 sigma limits\nfor the magnitudes.\n\nT0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic\n-------------------------------------------------------------------------------------------------------\n3.097       8:42:32.91          1140      >16.23     >15.42     >15.34\n-------------------------------------------------------------------------------------------------------\nT0+ : Elapsed time after the burst\nT-EXP: Total Exposure time\nWe used GSC2.3 catalog for flux calibration.",
  "circularId": 23649,
  "createdOn": 1547037259000,
  "email": "oeda@hp.phys.titech.ac.jp",
  "subject": "GRB190109A: MITSuME Akeno optical upper limits",
  "submitter": "Motoki Oeda at Tokyo Inst. of Tech.  <oeda@hp.phys.titech.ac.jp>",
  "eventId": "GRB 190109A"
}