GCN Circular 21454
Subject
GRB 170810A: Swift/UVOT Detection
Date
2017-08-11T04:04:43Z (8 years ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
GRB 170810A: Swift/UVOT Detection
S. J. LaPorte (PSU) and S. L. Gibson (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170810A
85 s after the BAT trigger (Gibson et al., GCN Circ. 21450).
A source consistent with the XRT position
(Goad et al. GCN Circ. 21451)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 12:31:45.33 = 187.93889 (deg.)
Dec (J2000) = +03:39:38.9 = 3.66081 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits 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 85 235 147 14.64 +/- 0.02
v 628 648 20 15.88 +/- 0.13
b 554 574 20 16.62 +/- 0.10
u 299 1493 281 >19.3
w1 677 1473 97 >18.9
w2 604 623 19 >18.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).