TITLE:   GCN CIRCULAR
NUMBER:  37683
SUBJECT: GRB 241002A: Swift/UVOT Upper Limits
DATE:    24/10/02 17:06:04 GMT
FROM:    Sam Shilling at Lancaster University <shilling.sam@gmail.com>

S. P. R. Shilling (Lancaster U.), S. R. Oates (Lancaster U.),
N. P. M. Kuin (UCL-MSSL) and R. Caputo (GSFC) report on behalf
of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 241002A
116 s after the BAT trigger (Caputo et al., GCN Circ. 37662).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al., GCN Circ. 37665) 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           116          266          147         >19.9
white		   4616		10268	     1081	 >21.4
v		   5027		16800	     1081	 >19.8
b		   4412		5944	     292	 >19.8
u		   4206		5841	     393	 >19.6
uw1		   5437		5637	     197	 >19.0
uw2		   4822		11104	     1014	 >20.5
um2		   5232		22035	     1477	 >20.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.011 in the direction of the burst
(Schlegel et al. 1998).