[vsnet-grb-info 17964] GRB 160509A: Swift/UVOT Upper Limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19412
SUBJECT: GRB 160509A: Swift/UVOT Upper Limit
DATE:    16/05/09 17:54:45 GMT
FROM:    Frank Marshall at GSFC  <femarsha at khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and T.G.R. Roegiers (PSU) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the Swift-XRT afterglow
(Kennea et al., GCN Circ. 19408) 7259 s after the LAT trigger 
(Longo et al., GCN Circ. 19403). No UVOT source consistent with the position 
of Swift-XRT afterglow or the position of the optical afterglow
candidate (Levan et al., GCN Circ. 19410) is found in the initial exposure.
The preliminary upper limit using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) is:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

u                7259         7531          268          >20.5 

The magnitude in the table is not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.31 in the direction of the burst
(Schlegel et al. 1998).