GCN Circular 11213
Subject
Optical observations of GRB 100901A
Event
Date
2010-09-05T13:54:39Z (15 years ago)
From
AAVSO GRB Network at AAVSO <matthewt@aavso.org>
Stefano Sposetti (Gnosca, Switzerland) reports to the AAVSO International
High Energy Network the following optical observations of GRB 100901A (GCN
#11159, Immler et al.):
Stefano Sposetti reports a clear detection of the optical afterglow of GRB
100901A (GCN #11159, Immler et al., and many subsequent reports), and
obvious fading over the four hour span of observations. The afterglow was
observed unfiltered (R-band zero point) beginning at 23:25UT on 2010
September 01 (approximately 10 hours post-burst), and continuing to 03:50
UT on 2010 September 02. Observations were made using an SBIG ST8XE CCD
attached to a 0.4-m Newtonian sited in Gnosca, Switzerland. A total of
sixty 30-second integrations and 215 60-second integrations were obtained.
An ensemble of stars from the USNO-A2.0 catalog were used for the
magnitude comparison. The frames were co-added into sixteen frames of
15-minutes duration each, to enable time-series photometry.
Signal-to-noise in all of the images was between 24 and 52.
The following time-series data were derived:
date mag(CR)
Sept 1.98105 17.43
Sept 1.99242 17.50
Sept 2.00391 17.49
Sept 2.01520 17.53
Sept 2.02619 17.66
Sept 2.03711 17.67
Sept 2.04803 17.57
Sept 2.05896 17.63
Sept 2.07011 17.66
Sept 2.08135 17.72
Sept 2.09257 17.83
Sept 2.10413 17.79
Sept 2.11637 17.80
Sept 2.12767 17.79
Sept 2.13897 17.85
Sept 2.15026 17.91
The AAVSO High Energy Network was made possible through grants from the
Charles Curry Foundation and NASA.