GCN Circular 23241
Subject
GRB180914B: Swift UVOT detection of an optical afterglow
Date
2018-09-16T16:05:06Z (6 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. Paul M. Kuin reports on behalf of the Swift-UVOT team:
Swift-UVOT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 180914B (Bissaldi et al. GCN Circ. 23232)
in a series of observations tiled on the sky.
Within the error of the location of the XRT source (D'Ai, GCN Circ. 23236)
we detect a source that appears to be fading.
The UVOT source location is RA = 332.2609, Dec = 24.5823 deg which is
RA = 22:09:25.53 (J2000)
Dec = +25:03:43.8 (J2000)
which is consistent with Zheng and Filipenko (GCN Circ. 23237).
The preliminary magnitude using the UVOT photometric calibration
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) is
filter Tstart Tend exposure magnitude
u 8.35e4 8.37e4 76.5 18.90 +- 0.23
u 8.70e4 8.74e4 373.0 18.87 +- 0.11
u 9.27e4 9.29e4 1.93.8 19.05 +- 0.17A
Times in seconds since Tzero=2018-09-14 18:22:40 UT.
No correction has been made for Galactic interstellar reddening of
E(B-V) = 0.07 (Schlafy&Finkbeiner, 2011 ApJ 737, 103).