[vsnet-grb-info 10349] GRB 110312A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11787
SUBJECT: GRB 110312A: Swift/UVOT Upper Limits
DATE:    11/03/13 13:26:40 GMT
FROM:    Samantha Oates at MSSL  <sro at mssl.ucl.ac.uk>

S. R Oates (UCL-MSSL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110312A
168 s after the BAT trigger (Oates et al., GCN Circ. 11782).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 11784) is detected in the initial UVOT  
exposures.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
----------------------------------------------------------------
white_FC           168          318          147         >21.8
u_FC               327          577          246         >20.1
white              168         1896          429         >21.3
v                  657         1946          156         >19.2
b                  582         6063          315         >20.6
u                  327         2020          382         >20.1
w1                 706         1995          136         >19.6
m2                 682         1970          156         >19.6
w2                1036         1402           39         >18.8

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).