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GCN Circular 8737

GRB 081226A: Swift UVOT Upper Limits
2008-12-26T18:03:45Z (15 years ago)
Erik Hoversten at Swift/Penn State <>
E. A. Hoversten (PSU) and O. Godet (U Leicester) report on behalf of
the Swift UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 08226A 156s after the BAT trigger (Godet et al., GCN 8729).
We do not detect any source at the Swift XRT position.  The white
filter observation was skipped due to a 7th magnitude star in the field.
The UVOT upper limits are around 20th magnitude so the non-detections do
not conflict with the possible optical afterglow detections in GCN
8731 and GCN 8732 at 24th magnitude.  UVOT magnitude 3-sigma upper
limits are reported in the following table:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
v          461      2276     233         > 19.24
b          410      2226     228         > 20.13
u          155      2051     833         > 20.87
uvw1       510      2176     213         > 19.71
uvm2       486      2151     213         > 19.51
uvw2       436      2252     233         > 19.83

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.16 mag.
All photometry is on the UVOT photometric system described in Poole et
al. (2008, MNRAS, 383, 627).
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