[vsnet-grb-info 4395] GRB 070306 Swift/UVOT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6177
SUBJECT: GRB 070306 Swift/UVOT refined analysis
DATE:    07/03/07 13:34:33 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp at mssl.ucl.ac.uk>

  M. De Pasquale, S.B. Pandey (MSSL/UCL) report on the behalf of
the Swift UVOT team:

  Swift/UVOT observed the field of GRB070306 (Pandey et al. 2007, GCN 6169)
starting 146s after the trigger with the settling expsoure.

  UVOT did not find any source inside the refined XRT error circle
(Page et al. 2007, GCN  6172), down to the following 3 sigma upper
limits in the White filter finding exposure and in the coadded
frames in all filters:


Filter  t_start(s)  t_stop(s)  Exp(s)  Mag 3-sig UL

Wh_find      162      262       98         19.8

V            267    11158     1259         20.5
B            745     6257      403         21.5
U            721     6053      413         21.0
W1           697     5848      236         19.0
M2           673     5633      236         18.7
W2           773     6651      397         19.5
Wh           162     6462      512         20.7

These upper limits are not corrected for the small Galactic extinction,
corresponding to a reddening of E(B-V)=0.03 (Schlegel et al. 1998), 
towards the direction of this burst.