[vsnet-grb-info 4997] UVOT observations of SAXJ1810.8-2609

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6707
SUBJECT: UVOT observations of SAXJ1810.8-2609
DATE:    07/08/05 17:31:16 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps at mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and A.M. Parsons (GSFC) report on behalf of the 
Swift-UVOT team:

The Swift/UVOT observed the field of SAXJ1810.8-2609 (trigger=287042) 
starting 70 s after the BAT trigger (Parsons et al. 2007, GCN Circ.6706). 
On refined analysis of the UVOT data, a fading source is detected in the 
white-band filter at the position of SAX J1810.8-2610. The source is not 
detected in any other of the filters, in either single or coadded 
exposures.

The white band magnitude and 3-sigma upper limits in the other UVOT 
filters are as follows:

Filter  Tmid   Exposure	Magnitude
         (s)    (s)
white	119    98       19.25+/-0.12
         915    98       20.32+/-0.28
v       585    435      > 19.75
b       737    19       > 18.90
u       717    39       > 19.11
uvw1    693    39       > 18.65
uvm2    668    39       > 18.32
uvw2    772    39       > 18.76

where Tmid is the weighted mean time of the coadded exposures. The values 
quoted above are not corrected for the expected Galactic extinction 
corresponding to a reddening of E_{B-V} = 0.95 mag in the direction of the 
burst (Schlegel et al. 1998).