[vsnet-grb-info 1758] GRB 050713A: Swift/UVOT observation

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3598
SUBJECT: GRB 050713A: Swift/UVOT observation
DATE:    05/07/13 18:19:27 GMT
FROM:    Alexander Blustin at MSSL-UCL  <ajb at mssl.ucl.ac.uk>

A. Blustin (MSSL), A. Falcone (PSU), D. Hinshaw
(GSFC-SPSYS), P. Meszaros (PSU) report on behalf of
the Swift UVOT team:

Using summed images from Swift/UVOT of the field of
GRB 050713A, taken from 75 seconds after the BAT
trigger, no new source is detected within the XRT
error circle (Falcone et al., GCN 3581) in any of
the six filters down to the following 3-sigma
magnitude upper limits:

Filter   Exposure (s)  T_mid (s)   3-sig limit
V        129           252         17.98
B        36            351         18.08
U        39            309         17.81
UVW1     39            325         16.85
UVM2     39            311         17.13
UVW2     29            326         17.08

where T_mid is the mid-point of the summed observation.
The image background is significantly higher than
expected at this location due to the proximity of a 
6.56 V magnitude star (HD 204408).

We caution that the instrument is not yet fully
calibrated and that the magnitude limits presented here
may need to be refined.