GCN Circular 9908
Subject
GRB 090912: Swift/UVOT Upper Limits
Event
Date
2009-09-13T12:54:57Z (16 years ago)
From
Peter Curran at MSSL <pac@mssl.ucl.ac.uk>
P.A. Curran (MSSL-UCL) and T. N. Ukwatta (GSFC/GWU) report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090912 796s after
the BAT trigger (Ukwatta et al., GCN 9905). No optical afterglow consistent
with the enhanched Swift XRT position (Beardmore et al., GCN 9906) is detected
in the UVOT exposures. Preliminary 3-sigma upper limits, using the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627), for the first finding
chart (FC) and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 796 946 147 >20.50 (FC)
white 796 7707 608 >21.09
v 1129 8118 294 >19.04
b 1228 7502 254 >19.91
u 1204 7297 313 >19.58
w1 1179 7092 313 >19.82
m2 6688 8273 344 >19.78
w2 7713 7913 197 >19.78
The values quoted above are not corrected for the Galactic extinction due to
the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al.
1998).