GCN Circular 3901
Subject
GRB050827: Swift/UVOT upper limits
Event
Date
2005-08-29T02:25:11Z (20 years ago)
From
Alexander Blustin at MSSL-UCL <ajb@mssl.ucl.ac.uk>
A. J. Blustin (UCL-MSSL), M. Capalbi (ASDC), F. Marshall (GSFC),
J. Nousek (PSU), N. Gehrels (GSFC) on behalf of the Swift UVOT team
Swift/UVOT began observing the field of GRB050827 17.8 hours after
the BAT trigger (Capalbi, et al., GCN 3893); previous to that, the
target was unobservable due to a moon constraint. No new source with
respect to the DSS image is detected in the XRT error circle
(Capalbi, et al., GCN 3899) down to the following upper limits in
the six filters:
Filter T-range (hrs) Exp (s) 3sig_limit
V 20.9-24.3 1800 20.1
B 19.5-26.2 2444 21.0
U 19.3-25.9 2699 21.1
UVW1 18.1-25.7 2939 20.6
UVM2 17.8-24.6 2531 20.7
UVW2 20.6-24.1 1800 20.8
Where T_range is the time range in hours post-trigger over which the
summed images were accumulated and Exp is the total exposure time
(in seconds) of the summed image. The magnitude upper limits are not
corrected for extinction.
These magnitudes are based on preliminary zero-points, measured
in orbit, and will require refinement with further calibration.