{
  "bibcode": "2011GCN.12333....1M",
  "body": "A. S. Moskvitin, V. V. Sokolov, O. I. Spiridonova (SAO RAS, Russia),\nM. V. Andreev, A. V. Sergeev, N. A. Parakhin (Terskol Branch of Institute of\nAstronomy, Russia)\n\nWe observed the field of GRB 110731A (Oates et al., GCN 12215) on July, 31\nwith 0.6-m Zeiss-600 (Terskol Branch of Institute of Astronomy,  Russia)\nequipped with the PixelVision Vienna CCD (1024 x 1024, bin 2 x 2)\n+ R filter, and 1-m Zeiss-1000 (SAO RAS, Russia) equipped with the\nE2V 42-40 CCD (2048 x 2048, bin 2 x 2) + B and Rc filters. In both cases\nthe observations carried out at a high airmass and with the seeing ~4\".\n\nAt all stacked images we did not detect any source within the Swift/UVOT\nerror circle (Oates., GCN 12222). Close to the error circle are visible two\nobjects which are also present in the USNO-B.1 catalogue:\nS1: USNO-B.1 0614-0802286 (R.A.=18:42:00.72, Dec.=-28:32:14.9, E.=2000.0) &\nS2: USNO-B.1 0614-0802328 (R.A.=18:42:01.24, Dec.=-28:32:11.6, E.=2000.0).\nOur astrometric calibration and photometry of S1 object showed\nthat it can contain flux from OT but due to large seeing we can not\ndistinguish bright S1 and faint OT.\n\nAll three co-added images are shown at\nftp://ftp.sao.ru/pub/grb/GRB110731A/GRB110731A.jpg\nUpper limits are shown at the following table.\n_________________________________________________________\nmid. time, UT   filter exp., sec  3-sigma lim. telescope\n_________________________________________________________\n19:15           R      53 x 200   19.9        Zeiss-600\n19:24           Rc     31 x 60    21.7        Zeiss-1000\n19:38           B      22 x 60    20.8        Zeiss-1000\n_________________________________________________________\n\nWe use USNO-B.1 star 0614-0802353 (R.A.=18:42:01.83, Dec.-28:32:23.9,\nE.=2000.0,  B2 = 15.77, R2 = 14.29) as a standard, and did not apply Galaxy\nextinction correction.\n\nThis message can be cited.",
  "circularId": 12333,
  "createdOn": 1315557016000,
  "email": "sokolov@sao.ru",
  "subject": "GRB 110731A: SAO RAS and Terskol observations",
  "submitter": "Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>",
  "eventId": "GRB 110731A"
}