GCN Circular 6442
Subject
GRB 070520B: Swift/UVOT Upper Limits
Date
2007-05-21T20:04:41Z (17 years ago)
From
Frank Marshall at GSFC <marshall@milkyway.gsfc.nasa.gov>
F.E. Marshall (NASA/GSFC) and A. Moretti (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 070520B starting 107 s after
the BAT trigger (Moretti et al., GCN Circ. 6425). We do not find any source
in any of the UVOT observations inside the refined XRT error circle
(Moretti et al., GCN Circ. 6438). The 3-sigma upper limits for detecting
a source inside the XRT error circle in the first finding chart (FC)
exposure and co-added frames are:
Filter T_start(s) T_stop(s) Exp(s) Mag (3-sigma UL)
White (FC) 107 207 98 >20.3
White 107 6197 491 >21.0
V 213 11338 1356 >20.1
B 4360 5992 393 >20.3
U 4155 5788 393 >20.0
UVW1 3950 5583 393 >19.9
UWM2 3745 12043 1094 >20.5
UVW2 4769 10411 1152 >20.9
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V) = 0.04 mag towards
the direction of the burst (Schlegel et al. 1998).
[GCN OPS NOTE(03jun07): Per author's request, the typo in the Subject-line
was changed from "075020B" to "070520B".]