{
  "bibcode": "2006GCN..4652....1B",
  "body": "I. Bikmaev, A.Galeev, N. Sakhibullin (KSU/AST)\nI. Khamitov, Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.),\nR. Burenin, M. Pavlinsky, R. Sunyaev (IKI)\n\nreport:\n\nThe field of XRT position of GRB 060203 (Swift BAT Trigger 180151,\nRetter et al., GCN 4641, GCN 4644) was  observed with Russian-Turkish\n1.5-m telescope (RTT150, Bakyrlytepe, TUBITAK National Observatory,\nTurkey) by using Andor CCD.\n\nWe made series of 30 sec exposures in Rc and V filters, and series\nof 60 sec exposures in B-filter on February 04, 00:20 - 03:50  UT.\n\nWe confirm the presence of the fading optical transient found  by\nMalesani et al. (GCN 4645) and Genko et al. (GCN 4646) and\nestimate its magnitudes (relative to R = 18.1, V = 18.7, and B = 19.6\nof nearby USNO star U1575_02633321) on our co-added frames as follows:\n\nRc = 19.9 +-0.1  UT(mean) = 00:49  ( 54 min after the burst)\nV  = 22.3 +-0.3  UT(mean) = 01:33  ( 98 min   )\nB  > 23          UT(mean) = 02:07  ( 2h 12 min)\nRc = 21.0 +-0.1  UT(mean) = 02:49  ( 2h 54 min)\nV  > 22.5        UT(mean) = 03:05  ( 3h 10 min)\n\n\nBy using our and published R magnitudes the estimated\npower law decay slope is -0.90+/-0.04\n(http://www.tug.tubitak.gov.tr/~irekk/grb/grb060203/grb060203.jpg)\n\nThe red spectrum of OT is supporting also by IR data of Bloom et al. (GCN 4648).\n\n\nThis message may be cited.",
  "circularId": 4652,
  "createdOn": 1139038782000,
  "email": "irekk@tug.tug.tubitak.gov.tr",
  "subject": "GRB 060203: RTT150 optical observations",
  "submitter": "Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>",
  "eventId": "GRB 060203"
}