GCN Circular 12286
Subject
GRB 110818A: Swift/UVOT Upper Limits
Date
2011-08-19T19:29:06Z (13 years ago)
From
Tyler Pritchard at PSU <tapritchard@astro.psu.edu>
T. A. Pritchard (PSU) and C. B. Markwardt (NASA/GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 110818A
379 s after the BAT trigger (Markwardt et al., GCN Circ. 12279).
No optical afterglow consistent with the Enhanced Swift-XRT position
(GCN Circ. 12285) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
v 379 14423 1513 >20.8
b 477 18642 2455 >22.2
u 452 8009 813 >20.4
w1 428 7804 646 >20.9
m2 7399 7599 197 >20.9
w2 6989 13752 1082 >21.2
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).