GCN Circular 2792
Subject
GRB 041006: BR observations with VATT
Event
Date
2004-10-09T03:29:13Z (22 years ago)
From
Krzysztof Z. Stanek at CfA <kstanek@cfa.harvard.edu>
P. Garnavich, X. Zhao, T. Pimenova (Notre Dame)
We observed the field of the afterglow of GRB 041006 reported by Noel & Price
(GCN 2765) with the 1.8-m Vatican Advanced Technology Telescope (VATT) beginning
on Oct. 8.251 (UT) (1.74 days after the burst). Exposures totaling 25 minutes
in R and B were obtained in 1" seeing. Standard stars were also observed
and color terms applied to two local standards:
RA (J2000) Dec R B
Star A 00:54:47.044 +01:14:05.61 17.71 (04) 18.24 (04)
Star B 00:54:54.494 +01:15:47.81 16.28 (04) 17.95 (04)
showing that the USNO A2.0 red magnitudes are 0.4 mag too bright for this
field as noted by Fugazza et al. (GCN 2782) and that the B-mags are way
off.
The optical transient is measured to be R=22.31 (05) and
B=23.09 (06) mag. The reddening in this direction (Schlegel et al. 1998)
is E(B-V)=0.026 mag so the intrinsic color is B-R=0.737 mag. corresponding
to a power-law spectral slope of -1.0.
This message can be cited.
[GCN OPS NOTE (09oct04 13:00 UT): As per author's request,
the "2.25 days after" was changed to "1.74 days after".]