TITLE:   GCN CIRCULAR
NUMBER:  16432
SUBJECT: GRB 140620A: Swift/UVOT Detection
DATE:    14/06/21 21:43:23 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) and M. De Pasquale (IASF-Palermo) report on behalf of the
Swift/UVOT team:

The Swift/UVOT observed the field of the Fermi/GBM-detected burst GRB 140620A
beginning 37.6 ks after the trigger (Fitzpatrick et al., GCN circ 16426). We confirm
the fading optical transient reported by iPTF (Kasliwal et al., GCN circ 16425) at
a position of:
  RA  (J2000) =  18:47:29.00 = 281.87082 (deg.)
  Dec (J2000) =  49:43:51.0  =  49.73085 (deg.)
with an uncertainty of 0.3 arcsec (radius, 90% confidence). This
is 0.7 arcsec from the iPTF position.

Preliminary detections using the UVOT photometric system (Breeveld et
al. 2011, AIP Conf. Proc. 1358, 373) are given in the following table:

Filter   T_start(ks)   T_stop(ks)   Exp(s)   Mag
u           37.6         43.9       1718     19.78+-0.10
u          124.0        125.3       1251     20.38+-0.18

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).