GCN Circular 15150
Subject
GRB 130831A: Montarrenti Observatory optical observations
Date
2013-09-01T01:07:49Z (12 years ago)
From
Simone Leonini at Monarrenti Obs <s.leonini@iol.it>
Simone Leonini, G. Guerrini, P. Rosi and L.M. Tinjaca Ramirez (Montarrenti
Observatory, Siena, Italy) report:
We observed the optical afterglow of GRB 130831A (Swift trigger 568849, Hagen
et al., GCN Circ. 15139) and slow fading over the four hours span of
observations with the automatic 0.53m RC telescope + U47 detector at
Montarrenti Observatory (Siena, Italy, IAU code C88).
The observations were started at 2013-08-31 20:18:04 UT (approximately 7 hours
post-burst) and continued to 00:29:36 UT on 2013-09-01 stacking 2 unfiltered
CCD exposures of 60s for each run.
The OT was detected in all frames. The resulting time-series are as follows:
2013 Aug 31.84588 UT R=18.22 +/- 0.21
2013 Aug 31.90427 UT R=18.55 +/- 0.21
2013 Aug 31.94019 UT R=18.47 +/- 0.22
2013 Aug 31.96977 UT R=18.63 +/- 0.23
2013 Aug 31.99955 UT R=18.95 +/- 0.22
2013 Sep 01.02056 UT R=19.09 +/- 0.21
Magnitudes were obtained using Astrometrica software using USNO-B1 catalogue
for positions and photometry. An ensemble between 38 and 66 stars were used for
the magnitude comparison.
The position of the GRB (within the error box given by Swift) is the
following:
RA (J2000.0) 23h 54m 29.90s +/-0.13
Decl. (J2000.0) +29�� 25' 46.8" +/-0.14
The message may be cited.