[vsnet-grb-info 6914] GRB 081109: Swift/UVOT upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8504
SUBJECT: GRB 081109: Swift/UVOT upper limits
DATE:    08/11/09 15:18:19 GMT
FROM:    Paul Kuin at MSSL  <npkuin at googlemail.com>

N. P. M. Kuin (MSSL/UCL) and S. Immler (CRESST/GSFC/UMD)
report on behalf of the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began observing
GRB 081109 (Swift BAT trigger number 334112; Immler et al.,
GCN Circ. 8500) on November 9, 2008, with a white filter finding
chart at 07:03:23 UT, 75 seconds after the trigger.

No new source is detected in any of our images at the position
consistent with the reported XRT position in GCN Circ. 8500.

The magnitudes and upper limits for GRB081109 at this position
are given below:

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh      75       6592     745      >21.49  (3-sigma UL)
u      287       6181     501      >20.57  (3-sigma UL)
b      543       6387     452      >20.35  (3-sigma UL)
uvw2   593       5362     274      >20.03  (3-sigma UL)
v      617       5566     274      >19.09  (3-sigma UL)
uvm2   641       5771     274      >19.87  (3-sigma UL)
uvw1   666       5976     255      >20.00  (3-sigma UL)

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383, 627). They are not corrected for
the expected galactic reddening of E(B-V) = 0.019 in the direction
of the burst (Schlegel et al. 1998).