{
  "bibcode": "2017GCN.20892....1Y",
  "body": "K. Yanagisawa, D. Kuroda, Y. Shimizu, H. Izumiura (OAO/NAOJ),\nM. Yoshida (Hiroshima), K. Ohta(Kyoto) and N. Kawai (Tokyo Tech.)\nreport on behalf of the MITSuME collaboration:\n\nWe observed the field of GRB 170317A (LaPorte et al., GCN 20885)\nin Ks-band with a wide-field near infrared imager at Okayama\nAstrophysical Observatory (Japan).  The imager has effective\naperture of 0.91 m.\n\nObservations started from 09:54 UT on 17th March, 8 min after\nthe BAT trigger, to 10:38 UT. The total exposure of 17.0 min\nwas successfully obtained.\n\nIn our co-add image, we did not find any new point source within\nthe XRT error circle (Beardmore et al., GCN 20887) down to\nthe limiting magnitude of Ks=16.1 (Vega, S/N=5). The photometric\ncalibration was made against 2MASS field stars.\n\nT0+[sec]    MID-UT     T-EXP[sec]      Ks\n---------------------------------------------------\n   +1,819    10:16      1020.0          >16.1\n---------------------------------------------------\nT0+ : Elapsed time after the burt [sec]\nT-EXP: Total Exposure time [sec]",
  "circularId": 20892,
  "createdOn": 1489768779000,
  "email": "yanagi@oao.nao.ac.jp",
  "subject": "GRB 170317A: MITSuME Okayama Ks-band upper-limit",
  "submitter": "Kenshi Yanagisawa at OAO/NAOJ  <yanagi@oao.nao.ac.jp>",
  "eventId": "GRB 170317A"
}