{
  "bibcode": "2006GCN..4496....1Y",
  "body": "K. Yanagisawa (OAO/NAOJ), H. Toda, and N. Kawai (Tokyo Tech) report\non behalf of the MITSuME collaboration: \n\n\"We have observed the field of GRB 060111B (Perri et al. GCN 4487,\nTueller et al. GCN 4492) with the three-color MITSuME 50 cm telescope\nat Okayama, Japan starting at 20:26:18 UT (T_burst+10.6 min) for an\neffective exposure of 45 min (60sec x 45).\n\nComparison of the two stacked images \nat midtime 20:28:56 UT (T_burst+13.2min, exp=60sec x5)  and \nat midtime 20:56:26 UT (T_burst+40.7min, exp=60sec x5) \nrevealed a fading object at the same location in the Rc and Ic band\nimages.   The coordinates of the fading object are:\n\nRA 19:05:42.47, DEC +70:22:33.1 (error = 0.3 arcsec)\n\nWe identify this object as the optical afterglow of GRB 05111B for the\nfollowing reasons:\n 1) these coordinates are consistent with those of the UVOT afterglow\ncandidate by Perri et al. (GCN 4487), and \n 2) while we do not confirm the possible host galaxy noted by Khamitov\net al. (GCN 4493) in our images, it is not likely to confuse our\nidentification as it is 4.2 arcsec away.\n\nThe magnitudes of the OT at midtime 20:28:56 UT (T_burst+13.2min) were\nfollowing: \n\n  \u001b$B!!\u001b(Bg': > 19.1 (3 sigma detection limit)\n    Rc:   18.9 +/- 0.4\n    Ic:   18.3 +/- 0.4\n\nThe Rc and Ic magnitudes were calibrated with the R2 and  I2 magnitudes\nof the USNO-B1.0 stars.  The g' magnitudes was derived from the NOMAD\nB, V magnitudes using the formula by Smith et al. (2002).\n\nThe images obtained at Okayama can be viewed at \nhttp://bragi.oao.nao.ac.jp/support/telescope/grb50/images/GRB060111B.pdf\"",
  "circularId": 4496,
  "createdOn": 1137077754000,
  "email": "nkawai@hp.phys.titech.ac.jp",
  "subject": "GRB 060111B: MITSuME detection of optical afterglow",
  "submitter": "Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>",
  "eventId": "GRB 060111B"
}