GCN Circular 9544
Subject
GRB 090621: Swift/UVOT Upper Limits
Event
Date
2009-06-21T12:29:18Z (17 years ago)
From
Peter Curran at MSSL <pac@mssl.ucl.ac.uk>
P.A. Curran (UCL-MSSL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090621
123 s after the BAT trigger (Curran et al., GCN 9540). No optical
afterglow consistent with the refined XRT position (Page et al., GCN
9543) 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 first exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
wh 123 7115 805 >21.5
v 613 6089 333 >19.4
b 538 6910 310 >20.5
u 282 6705 736 >20.5
uw1 662 6500 320 >19.8
um2 637 6295 333 >19.7
uw2 588 5884 333 >19.9
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).