GCN Circular 5625
Subject
GRB 060926: Swift-UVOT Detections
Date
2006-09-27T02:20:21Z (18 years ago)
From
Pete Roming at PSU <roming@astro.psu.edu>
P. Roming (PSU) and S. T. Holland (GSFC/USRA) report on behalf of the Swift-UVOT
team:
The Swift UVOT began observing GRB 060926, 57 seconds after the BAT trigger (GCN
5612). We detect a source at the 4.8- and 4.3-sigma levels in the V- and UVW1-
(251 nm) filters, respectively. The magnitude of the source is 19.0+/-0.2
(V-filter) and 18.8+/-0.2 (UVW1-filter) as determined by the Swift analysis
tool, uvotsource.
No optical afterglow is detected at the 3-sigma level in individual or coadded
exposures in the UVOT UVW2-, UVM2-, U-, or B-filters. The 3-sigma limiting
magnitudes for the coadded images of the UVOT filters are listed below:
Filter T_range(s) Exp(s) Upper Limit (3-sigma)
UVW2 551-6405 432 20.1
UVM2 463-10840 1366 20.4
U 511-12283 968 20.8
B 535-6199 422 20.6
where T_range is the start and end times of the coadded exposures. No correction
has been made for Galactic reddening along the line of sight (E(B-V) = 0.16).
No images were taken in the White-filter by the UVOT since bright stars were in
the field-of-view.