TITLE:   GCN CIRCULAR
NUMBER:  19795
SUBJECT: GRB 160815A: Swift/UVOT Afterglow Detection
DATE:    16/08/15 13:03:44 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and C. B. Markwardt (NASA/GSFC) 
report on behalf of the Swift/UVOT team:

The Swift/UVOT has discovered an optical afterglow for 
GRB 160815A (Markwardt et al., GCN Circ. 19794) in
an exposure with the white filter.

The preliminary UVOT position is:
   RA  (J2000) =  19:14:09.63 = 288.5401 (deg.)
   Dec (J2000) =  +84:18:50.4  =  84.3140 (deg.)
with an estimated uncertainty of 1.0 arcsec. (radius, 90% confidence).

The preliminary magnitude 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

white           863        1013          150          19.1

The magnitude is not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.12 in the direction of the burst
(Schlegel et al. 1998).