{
  "bibcode": "2013GCN.15150....1L",
  "body": "Simone Leonini, G. Guerrini, P. Rosi and L.M. Tinjaca Ramirez (Montarrenti \nObservatory, Siena, Italy) report:\n\nWe observed the optical afterglow of GRB 130831A (Swift trigger 568849, Hagen \net al., GCN Circ. 15139) and slow fading over the four hours span of \nobservations with the automatic 0.53m RC telescope + U47 detector at \nMontarrenti Observatory (Siena, Italy, IAU code C88).\n\nThe observations were started at 2013-08-31 20:18:04 UT (approximately 7 hours \npost-burst) and continued to 00:29:36 UT on 2013-09-01 stacking 2 unfiltered \nCCD exposures of 60s for each run.\n\nThe OT was detected in all frames. The resulting time-series are as follows:\n\n2013 Aug 31.84588 UT R=18.22 +/- 0.21 \n2013 Aug 31.90427 UT R=18.55 +/- 0.21\n2013 Aug 31.94019 UT R=18.47 +/- 0.22\n2013 Aug 31.96977 UT R=18.63 +/- 0.23\n2013 Aug 31.99955 UT R=18.95 +/- 0.22\n2013 Sep 01.02056 UT R=19.09 +/- 0.21\n\n\nMagnitudes were obtained using Astrometrica software using USNO-B1 catalogue \nfor positions and photometry. An ensemble between 38 and 66 stars were used for \nthe magnitude comparison.\n\nThe position of the GRB (within the error box given by Swift) is the \nfollowing:\n\nRA    (J2000.0)  23h 54m 29.90s +/-0.13\nDecl. (J2000.0) +29�� 25' 46.8\"  +/-0.14\n\nThe message may be cited.",
  "circularId": 15150,
  "createdOn": 1377997669000,
  "email": "s.leonini@iol.it",
  "subject": "GRB 130831A: Montarrenti Observatory optical observations",
  "submitter": "Simone Leonini at Monarrenti Obs  <s.leonini@iol.it>",
  "eventId": "GRB 130831A"
}