GCN Circular 13701
Subject
GRB 120817A: Swift/UVOT Upper Limits
Date
2012-08-27T23:33:50Z (12 years ago)
From
Stefan Immler at NASA/GSFC <stefan.m.immler@nasa.gov>
S. Immler (NASA/CRESST/GSFC) and B. P. Gompertz (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 120817A
3115 s after the BAT trigger (Gompertz et al., GCN Circ. 13661).
No optical afterglow consistent with the XRT (Beardmore et al., GCN
13667) or the FTN positions (Guidorzi et al., GCN 13664) is detected
in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 3115 3265 147 >19.4
white 3115 4496 344 >20.4
v 3272 10816 1278 >20.2
b 4092 17166 945 >21.1
u 3887 22943 1904 >21.1
w1 3682 22294 2164 >20.3
m2 3476 21386 1838 >20.2
w2 4503 9902 1082 >20.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.84 in the direction of the burst
(Schlegel et al. 1998).