{
  "bibcode": "2012GCN.13235....1V",
  "body": "A. Volnova (SAI MSU),  D. Varda (ISON), E. Sinyakov (ISON),  E. Litvinenko \n(UBAI), V. Kouprianov (GAO), I. Molotov (KIAM), A. Pozanenko (IKI) on behalf \nof  larger GRB follow up collaboration report:\n\nWe observed the field of the Swift GRB 120404A  (Stratta et al., GCN 13208) \nwith ORI-25 (0.25-m) telescope of  ISON-Blagoveschensk observatory between \nApr. 04 (UT) 13:06:10 - 14:43:45 and ORI-40 (0.4-m) telescope of ISON-Kitab \nobservatory between Apr. 04 (UT) 17:13:02 - 18:16:58.  Several unfiltered \nimages were taken in both observatories. We detected optical afterglow \n(Stratta et al., GCN 13208; Guidorzi et al., GCN 13209) in combined image \n(see below).  Coordinates of the OT are (J2000) 15:40:02.17,  +12:53:06.5 \nwith unceraininty of 0.75\" on both coordinates which is compatible with \ncoordinates reported by UVOT team (Stratta et al.,  GCN 13208). A photometry \nis based on nearby USNO-B1.0 stars (R2 magnitude):\n\nt_start,    t-t0 (mid),  filter  exp.,    OT,                UL\n(UT)             d                   s\n\n13:06:10 0.01529  none  12x25   n/d                   16.5\n13:21:11 0.03700  none  38x25   17.35 +/- 0.25 17.5\n14:08:43 0.06611  none  29x25   n/d                   17.9\n17:13:02 0.20378  none  60x60   n/d                   18.9\n\nBased on initially non-detection of the OT we can confirm the brightening of \nthe afterglow (Breeveld et al., GCN 13226;  Tristram et al., GCN 13228; \nGorbovskoy  et al., GCN 13230) with a peak between (UT) 13:21 and 14:06 \n(i.e. ~ 50 min after burst trigger).",
  "circularId": 13235,
  "createdOn": 1333838419000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 120404A: optical observations",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 120404A"
}