[vsnet-grb-info 10988] GRB 110928A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12406
SUBJECT: GRB 110928A: Swift/UVOT Upper Limits 
DATE:    11/09/28 20:38:28 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten at astro.psu.edu>

E. A. Hoversten (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110928A
3342 s after the BAT trigger (Hoversten et al., GCN Circ. 12394).
No optical afterglow consistent with the XRT position (Osborne et al.,
GCN Circ. 12402) 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          3342         3492          147         >20.2
white             3342         4723          344         >21.0
v                 3499         3698          197         >19.1
b                 4319         4518          197         >21.0
u                 4114         4313          197         >20.8
w1                3909         4108          197         >20.3
m2                3704         3903          197         >19.9
w2                4729         4929          197         >21.6

The magnitudes in the table are not corrected for the Galactic  
extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).