[vsnet-grb-info 4002] GRB 061110A: refined R-band analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5817
SUBJECT: GRB 061110A: refined R-band analysis
DATE:    06/11/12 16:07:43 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene at astro.ku.dk>

Christina C. Thoene and Johan P. U. Fynbo (DARK Cosmology Centre) report:

We further analysed our R-band data of the afterglow of GRB 061110A taken
with ALFOSC/NOT (GCN 5799) and FORS1/VLT (GCN 5812).
Crosscalibration of the two observation sets with a nearby star
(RA=22:25:07.76, Dec=-02:15:00.52) and zeropoints from the ESO webpages
gives revised  magnitudes of R=23.3 at 8h after the burst (NOT) and
R=23.9 at 14h (VLT), where we assume R=22.1 for the magnitude of
the star. The offset to the magnitudes reported earlier are due to old
ALFOSC zeropoints and refined reduction.

Together with the magnitude reported in GCN 5798, we find that a single
powerlaw decay with a slope of alpha=0.83 +- 0.08 fits the data well. A
plot of the lightcurve can be found at

www.astro.ku.dk/~cthoene/GRBs