[vsnet-grb-info 8465] GRB 090929A: Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9981
SUBJECT: GRB 090929A: Swift/UVOT Observations
DATE:    09/09/30 22:34:16 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at astro.psu.edu>

M. H. Siegel (PSU) and K. L. Page (U. Leicester) report on behalf
of the Swift/UVOT team.

Swift/UVOT began settled observations of GRB 090929A about 13 hours  
after
the burst (Rau, GCN Circ. 9962; Cummings & Krimm, GCN Circ. 9966;
Golenetskii et al., GCN Circ. 9968; Page, GCN Circ 9977).  Due to the
presence of a 9th magnitude (V) star 45" from the center of the BAT  
position,
data were only obtained in the UVM2 filter.

We do not detect any uncatalogued UV source within the BAT error circle.
The 3-sigma upper limit and summed exposure is reported below:

FILTER     T_start(s)  T_stop    Exposure     Mag/3UL
=============================================================
UVM2         47411      52924      2252            >21.26
=============================================================

This magnitude is not corrected for the Galactic extinction  
corresponding
to a reddening of E_{B-V} = 0.07 (Schlegel et al., 1998, ApJS, 500,  
525).
The photometry is on the UVOT photometric system described in Poole et  
al.
(2008, MNRAS, 383, 627).