GCN Circular 15032
Subject
GRB 130725B: Swift/UVOT Detection of an Optical Counterpart
Date
2013-07-25T21:56:37Z (11 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
M. H Siegel and C. A. Swenson (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 130725B
72 s after the BAT trigger (Swenson et al., GCN Circ. 15029).
A source consistent with the XRT position
(Swenson et al. GCN Circ. 15029)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 14:16:57.76 = 214.24068 (deg.)
Dec (J2000) = -11:07:41.8 = -11.12827 (deg.)
with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence).
Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 72 221 147 17.29 +/- 0.03
u 284 534 246 17.96 +/- 0.07
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.061 in the direction of the burst
(Schlegel et al. 1998).