{
  "bibcode": "2019GCN.25906....1M",
  "body": "K. L. Murata, R. Adachi,  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 191001B (E. Troja et\nal., GCN Circular #25902) with the optical three color (g', Rc, and\nIc) CCD cameras attached to the MITSuME 50 cm telescope of Akeno\nObservatory, Yamanashi, Japan.\n\nThe observation started on 17:22:09 UT. We did not find any new point\nsources within the BAT on-board calculated error circle in all three bands.\nWe obtained the following 5-sigma limits for the magnitudes.\n\nT0+[sec]   MID-UT    T-EXP[sec]    5-sigma limits\n------------------------------------------------------------------------------------------------\n~169       ~17:37    1680             g'>18.8, Rc>18.8, Ic>18.6\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 AB system.",
  "circularId": 25906,
  "createdOn": 1569955928000,
  "email": "murata@u.phys.nagoya-u.ac.jp",
  "subject": "GRB 191001B: MITSuME Akeno optical upper limits",
  "submitter": "Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>",
  "eventId": "GRB 191001B"
}