GCN Circular 11038
Subject
GRB 100802A: Swift/UVOT Possible Optical Afterglow
Date
2010-08-02T15:59:42Z (14 years ago)
From
Alice Breeveld at MSSL-UCL <aab@mssl.ucl.ac.uk>
A. Breeveld (MSSL/UCL) and E. Troja (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 100802A
89 s after the BAT trigger (Troja et al., GCN Circ. 11031). Using the
data from the most recent telemetry, there is a tentative detection of
an optical afterglow at the position given by Siegel et al., GCN Circ.
11032, in the early white and u exposures.
Preliminary detections and later 3-sigma upper limits using the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first
finding chart (FC) exposures and subsequent summed exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 89 238 147 20.7 � 0.24
u_FC 301 551 246 19.57 � 0.22
white 581 5566 327 21.85 � 0.48
(2.4 sigma sig)
v 632 5977 432 >20.6
b 557 6754 388 >21.2
u 706 6593 412 >20.92
w1 682 6388 432 >20.9
m2 657 6183 432 >20.6
w2 608 5772 432 >21.0
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.12 in the direction of the burst
(Schlegel et al. 1998).