GCN Circular 9786
Subject
GRB090813: Swift/UVOT upper limits
Event
Date
2009-08-13T13:16:46Z (16 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P. Schady (MSSL-UCL) and J.R. Cummings (NASA/UMBC) report on behalf of the
Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090813 88s
after the BAT trigger (Cummings et al., GCN Circ 9781). No new source is
detected within the XRT error circle or at the optical position reported
by Cenko (GCN Circ. 9783) in any of the individual or combined UVOT
filters.
The 3-sigma upper limits of detected a source at the position of the
optical afterglow reported by Cenko (GCN Circ. 9783) in the first white
band finding chart (fc) observation, and in consecutive coadded
observations for each of the UVOT filters are as follows:
Filter T_start(s) T_stop(s) Exp(s) Mag 3-sig UL
wh (fc) 88 237 147 > 20.55
wh 581 1894 264 > 21.35
vv 631 1943 156 > 19.39
bb 556 1869 136 > 20.29
uu 300 2017 382 > 20.44
w1 681 1992 156 > 19.73
m2 656 1967 156 > 19.41
w2 607 1919 156 > 19.83
The values quoted above are not corrected for the Galactic extinction due
to the large reddening of E(B-V) = 0.17 in the direction of the burst
(Schlegel et al., 1998). The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383, 627).