{
  "bibcode": "2013GCN.15190....1P",
  "body": "A. Pozanenko (IKI), A. Volnova (IKI), B. Hafizov (UBAI), O. Burhonov \n(UBAI) report on behalf of larger GRB follow-up collaboration:\n\nWe observed the afterglow  (Hagen et al., GCN  15139; Guidorzi et al., \nGCN 15140) of the Swift GRB 130831A (Hagen et al., GCN  15139)  with \nAZT-22 telescope equipped with SNUCAM of Maidanak observatory in R \nfilter.  A preliminary photometry of combined images is based on  SDSS \nstars (see at the bottom):\n\nT_start              T0+       Filter, Exposure, OT\n(UT)                 (mid, d)            (s)\n\n2013-09-02T13:58:23  2.0410    R       1x600     22.20 +/- 0.10\n2013-09-04T18:47:13  4.2555    R       5x600     22.53 +/- 0.07\n2013-09-05T18:57:03  5.2658    R       6x600     22.90 +/- 0.07\n\nA preliminary lc of the afterglow GRB 130831A based on our GCNs ##15185, \n15186, 15188, 15189  and reported in this circular can be found in \nhttp://grb.rssi.ru/GRB130831A/grb130831A_lc_preliminary.PNG\n\nA power-law decay of the lc between 0.1 days and 2 days after trigger is \n-1.68 +/- 0.06  and marginally consistent with power-law decay reported \nby Watson (GCN 15179).\n\nReference stars\n\nN\tSDSS id\t\t\tR(Lupton)errR\n1\tJ235443.71+292539.3\t13.491\t 0.016\n2\tJ235438.60+292547.3\t14.136\t 0.015\n3\tJ235423.64+292452.8\t17.120\t 0.016",
  "circularId": 15190,
  "createdOn": 1378599461000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 130831A: Maidanak optical observations",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 130831A"
}