[vsnet-grb-info 10843] GRB 110808A: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12264
SUBJECT: GRB 110808A: Swift/UVOT Detection
DATE:    11/08/08 19:04:03 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard at astro.psu.edu>

T. A. Pritchard (PSU) and G. Stratta (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110808A
120 s after the BAT trigger (Stratta et al., GCN Circ. 12256).
A source consistent with the Enhanced Swift-XRT position
(Goad et al., GCN Circ. 12257) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
     RA  (J2000) =  03:49:04.27 =  57.26780 (deg.)
     Dec (J2000) = -44:11:40.1  = -44.19448 (deg.)
with an estimated uncertainty of 0.64 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT 
photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              120          270          147         19.88 ± 0.14
white              57           559           19         18.48 ± 0.23
white              3996         4196         200         20.17 ± 0.16
v                  609          629           19 >18.7
b                  535          555           20         18.64 ± 0.32
u                  279          528          246         18.28 ± 0.09
u                  683          703           19         17.48 ± 0.25
u                  6062         6262         196 >20.62
w1                 658          678           19 >17.8
w2                 585          605           19 >18.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).