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GCN Circular 8478

GRB081104: Swift/UVOT Upper Limits
2008-11-04T20:35:43Z (16 years ago)
Peter Brown at PSU <>
P. J. Brown, C. A. Swenson (PSU), S. T. Holland, and A. M. Parsons (GSFC),
on behalf of the Swift/UVOT team.

The Swift Ultra-Violet/Optical Telescope (UVOT) began settled
observations of GRB 081104 (trigger 333666) 2638 seconds after the BAT
trigger (Parsons et al., GCN Circ. 8473). No afterglow is detected at the
XRT position (Mangano et al., GCN Circ. 8474) in any filter.
The limiting magnitudes (3-sigma in 5" radius apertures) in each
of the UVOT filters are as follows:

Filter  T_start(s)  T_stop(s)  Exp(s)  Mag UL (3sig)

white     2638      3882       209     >21.1
v         2794      9582       1082    >20.5
b         3614      3814       197     >20.4
u         3409      3609       197     >20.1
uvw1      3204      3404       197     >19.8
uvm2      2999      9874       479     >20.1
uvw2      2788      5368       197     >19.9

The values quoted above are in the UVOT photometric system (Poole et al.
2008, MNRAS, 383, 627).  They are not corrected for the expected
Galactic extinction corresponding to a reddening of E(B-V)=0.11 mag in
the direction of the burst (Schlegel et al. 1998).
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