{
  "bibcode": "2007GCN..6485....1S",
  "body": "D. Shakhovskoy, V. Rumyantsev (CrAO),  V. Biryukov (CrAO, SAI MSU),\nA. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:\n\nWe observed error box of GRB070520B (Moretti et al., GCN 6425) with AZT-11\n(1.25m)  telescope of CrAO  in R-band under not optimal weather conditions\n(seeing ~3.6 arcsec) on May 20 between (UT)18:47 and 19:21, i.e. starting 1\nhour after burst onset. The weather condition No object is found in a\nrefined XRT error box (Moretti et al., GCN 6438 ). Limiting magnitude of a\ncombined image is based on USANO A2.0:\n\nMid time (UT),  Exposure,    R_Lim (3sigma)\nMay 20.753      6x300        21.0\n\nThe combined image can be found in\nhttp://grb.rssi.ru/GRB070520B/GRB070520B_AZT11.gif\n\nThis message may be cited.\n\n[GCN OPS NOTE(02jun07): The binary attachment was removed as well as the\ndiagnostics from MIMEDefang reacting to that binary.]",
  "circularId": 6485,
  "createdOn": 1180801952000,
  "email": "rum@crao.crimea.ua",
  "subject": "GRB070520B: optical observations",
  "submitter": "Vasilij Rumjantsev at CrAO  <rum@crao.crimea.ua>",
  "eventId": "GRB 070520B"
}