GCN Circular 9784
Subject
GRB 090813: Liverpool Telescope afterglow confirmation
Date
2009-08-13T06:17:10Z (15 years ago)
From
James Smith at ARI,Liverpool John Moors U <rjs@astro.livjm.ac.uk>
R.J. Smith, I.A. Steele, Z. Cano (Liverpool JMU), C. Guidorzi (U.
Ferrara), C.G. Mundell, A. Melandri, S. Kobayashi, C.J. Mottram,
D.F. Bersier, (Liverpool JMU), A. Gomboc (U. Ljubljana), report on behalf
of a large collaboration:
On 2009 August 13 at 04:13:40.8 UT the 2-m Liverpool Telescope
automatically began observing the Swift GRB 090813 (Cummings et al.,
GCN Circ. 9781) using the r' and i' filters. We confirm the detection by
Gorosabel et al (GCN 9782) and Cenko et al (GCN 9783) of an optical
counterpart to the XRT source. We measure a position of 15:03:05.9
88:34:05.5 J2000 with an uncertainty of 1arcsec and further, confirm the
OT is fading. Ths position is 1 arcsec from and therefore conssitent from
that reported by Cenko et al (GCN 9783).
Mid Time Delay from BAT Total Exp Filter Mag
(UT) trigger (min) (s)
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04:13:45.8 3.05 10 R 19.36 +/- 0.13
04:18:11.9 7.48 120 R 19.90 +/- 0.05
04:20:58.2 10.25 120 I 18.11 +/- 0.02
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Both astrometry and photometry is calibrated and quoted with respect
to USNO-B.
Further observations are ongoing.