GCN Circular 5024
Subject
GRB060428A: Swift/UVOT observations.
Date
2006-04-28T15:30:29Z (18 years ago)
From
Massimiliano de Pasquale at MSSL-UCL <mdp@mssl.ucl.ac.uk>
M. De Pasquale (UCL-MSSL), V. Mangano (IASF Palermo) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began taking data on the field of GRB060428A
at 03:23:48 UT on 2006-04-28, 60 s after the BAT trigger
(Mangano et al., GCN 5014), with the settling exposure. In the
refined XRT error circle (Magano et al., GCN 5018), we find
a weak (4 sigma detection) optical source in the V band at
about V=20, not present in USNO B1.0 catalogue. This source
however appears to be constant throughout the observation,
thus further observations will be needed to determine if it
is the optical afterglow of this burst.
No other afterglow candidate was detected at the refined XRT
position in summed images from any of the filters down to the
following three-sigma upper limits.
Filter T_range(s) Exp(s) 3sig_UL
V 60-7526 1657 20.2
B 548-7116 442 20.5
U 524-13380 436 20.5
UVW1 500-12666 1358 20.0
UVM2 476-11758 1425 19.9
UVW2 563-7322 472 19.5
These upper limits are uncorrected for the strong estimated
Galactic reddening of E_{B-V} = 1.25 mag (Schlegel et al. 1998).