[vsnet-grb-info 9456] GRB 100704: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10934
SUBJECT: GRB 100704: Swift/UVOT Upper Limits
DATE:    10/07/04 15:22:17 GMT
FROM:    Patricia Schady at MPE/Swift  <msslba at googlemail.com>

N.P.M. Kuin (MSSL/UCL) and D. Grupe (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100704
96 s after the BAT trigger (Grupe et al., GCN Circ. 10929). No optical
afterglow consistent with the XRT position (Osborne et al., GCN
Circ. 10930) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using a 3" aperture in
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            96          246          147         >21.0
u_FC               308          558          246         >20.2
white               96         6544          746         >21.8
v                  638         6955          471         >20.0
b                  564         6339          452         >21.1
u                  308         6132          678         >21.1
w1                 688         5927          255         >21.1
m2                 662         7075          387         >20.2
w2                 613         6750          471         >20.7

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.17 in the direction of the burst
(Schlegel et al. 1998).