GCN Circular 4167
Subject
GRB051021B: Swift/UVOT Upper limits
Event
Date
2005-10-26T20:33:52Z (20 years ago)
From
Peter Brown at PSU <pbrown@astro.psu.edu>
P. J. Brown (PSU), A. Retter (PSU), F. Marshall (GSFC),
A. Smale (NASA HQ), N. Gehrels (GSFC)
on behalf of the Swift/UVOT team report:
Swift-UVOT observed the field of GRB 051021B
(BAT Trigger=160672; Retter et al. GCN 4126)
starting at 2005-10-21 23:33:11, 78 seconds after the burst.
No source was detected within the XRT error circle
(Racusin et al GCN 4128) during the first 200 second image
(Tmid=178 seconds after the burst) down to a 3 sigma
limiting magnitude of V=19. Using summed images,
we also did not detect a source in any of our 6 filters
down to the following 3-sigma magnitude upper limits:
Filter T_range(sec) Exp(sec) 3sigUL
V 78-19380 1779 19.9
B 444-17793 1634 21.1
U 390-13591 961 19.9
W1 336-12417 1199 19.5
M2 282-12005 1199 19.6
W2 553-18702 1940 20.0
White 498-926 100 19.5
Where T_range is time post-trigger.
We note that this position is near the galactic
plane, so the extinction and background in this line of sight are high.