GCN Circular 9822
Subject
GRB 090817: Swift/UVOT Upper Limits
Date
2009-08-17T15:58:28Z (15 years ago)
From
Alice Breeveld at MSSL-UCL <aab@mssl.ucl.ac.uk>
A. Breeveld (MSSL/UCL) and W. Baumgartner (GSFC) report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090817
11008 s after the INTEGRAL trigger (Beckmann et al., GCN Circ. 9815).
No new sources are found in the UVOT data at the position of the XRT
source (P.A. Evans et al., GCN Circ. 9819). Preliminary 3-sigma upper
limits using the UVOT photometric system (Poole et al. 2008, MNRAS,
383, 627) and a 3 arcsec radius aperture, for the initial summed
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 11516 17719 413 >21.3
v 11975 12398 416 >19.6
b 11058 17509 787 >21.2
u 11008 17157 78 >19.5
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.66 in the direction of the burst
(Schlegel et al. 1998).