{
  "bibcode": "2007GCN..6329....1Y",
  "body": "M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ) and\nN. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:\n\nWe performed optical imaging observation (g', Rc, and Ic) of the\nfield of GRB 070419A (Stamatikos et al. GCN 6302) with 50cm MITSuME\ntelescope at Okayama Astrophysical Observatory from UT 10:53 to\nUT 13:06 on Apr.19 2007.\n\nWe coadded 106 CCD frames for each band. Exposure time of each frame\nis 1 minute. We made flux calibration using a USNO B1.0 star close\nto the XRT position (12:10:57.57, +39:55:40.2, B=16.14, R=15.22,\nI=14.37; see Williams et al. GCN 6328, Cenko et al. GCN 6306). We\ndetected a faint source in g' band at the position of the optical\ntransient reported by Chornock et al. (GCN 6304). The g' band magnitude\nand three sigma limiting magnitudes for Rc and Ic bands of this source\nare listed below.\n\n---------------------------------------------------------------\nband   mid-UT          exp.time       brightness\ng'     Apr. 19 12:00   106 x 1 min.   20.9 +- 0.2 mag\nRc     Apr. 19 12:00   106 x 1 min.   > 21.5 mag (upper limit)\nIc     Apr. 19 12:00   106 x 1 min.   > 19.4 mag (upper limit)\n---------------------------------------------------------------",
  "circularId": 6329,
  "createdOn": 1177051684000,
  "email": "yoshida@oao.nao.ac.jp",
  "subject": "GRB 070419A: MITSuME Okayama Observations",
  "submitter": "Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>",
  "eventId": "GRB 070419A"
}