TITLE:   GCN CIRCULAR
NUMBER:  7642
SUBJECT: GRB080426: Swift/UVOT upper limits
DATE:    08/04/26 20:37:54 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S.R. Oates (UCL-MSSL) and H. Ziaeepour (UCL-MSSL) report on behalf of
the Swift/UVOT team.

The Swift/UVOT began settled observations the field of GRB 080426
(trigger 310219) 226 seconds after the BAT trigger (Ziaeepour, et al.,
GCN Circ. 7639). No afterglow is detected at the enhanced XRT position
(Beardmore, et al., GCN Circ. 7641) in any of the UVOT filters. The 3 
sigma upper limits are given below:

Filter   T_start  T_stop    Exp.    Mag UL (3sig)
            (s)    (s)
------------------------------------------------
white      226     326       98        >20.38
white      446     7457     362        >20.86
v          333     7868    1316        >19.98
b          431     7253     303        >20.01
u          407     7047     333        >19.79
uvw1       382     6843     352        >19.99
uvm2       357     7969     407        >19.94
uvw2       462     7663     510        >20.26
-------------------------------------------------

These upper limits are not corrected for the Galactic extinction in
the line of sight, corresponding to a reddening of E(B-V)= 0.798 mag
(Schlegel et al., 1998, ApJS, 500, 525). The photometry is based on
the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 
627).