TITLE:   GCN CIRCULAR
NUMBER:  42100
SUBJECT: GRB 251003A: Swift/UVOT Upper Limits
DATE:    25/10/03 18:33:33 GMT
FROM:    s.shilling@lancaster.ac.uk

S. P. R. Shilling (Lancaster U.), M. De Pasquale (Univ. Messina) and 
A. P. Beardmore (U. Leicester) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 251003A
79 s after the BAT trigger (Beardmore et al., GCN Circ. 42070).

No optical afterglow consistent with the enhanced XRT position (Evans
et al., GCN Circ. 42088) or those reported by other instruments (Aceituno et al., 
GCN Circ. 42072; Moreno Méndez et al., GCN Circ. 42073; Strausbaugh et al., GCN 
Circ. 42074; Worssam et al., GCN Circ. 42094), 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                  79          229          147          >20.70
u                     291          474          180          >19.78
v                   33828        34558          711          >20.01
b                   43530        43837          298          >20.30

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.408 in the direction of the burst
(Schlegel et al. 1998).