GCN Circular 9410
Subject
GRB 090519: NOT refined analysis
Date
2009-05-20T14:53:33Z (15 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@astro.ku.dk>
D. Malesani (DARK/NBI), C.C. Thoene (INAF/Brera), P. Jakobsson (Univ.
Iceland), A.J. Levan (Univ. Warwick) J.P.U. Fynbo, B. Milvang-Jensen
(DARK/NBI), report on behalf of a larger collaboration.
We provide further analysis of the photometric data on the afterglow of
GRB 090519 (Perri et al., GCN 9400) taken at the NOT and VLT (Thoene et
al., GCN 9403; Levan et al., GCN 9409).
Calibration of the field based on archival VLT zeropoints yields a
significantly fainter magnitude for the afterglow with respect to our
previous GCN 9403, which was based on USNO stars. The new calibration is
consistent with SDSS stars and with the value reported by Rossi et al.
(GCN 9408). We find for the afterglow R = 22.8 on 2009 May 19.897 UT
(0.33 hr after the GRB).
The decay of the afterglow is well described by a power law with index
alpha = 0.44 +- 0.03 between 0.33 and 3.6 hr after the GRB.