GCN Circular 17531
Subject
GRB 150301B: Swift/UVOT Observations
Event
Date
2015-03-02T14:28:45Z (11 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
M. M. Chester (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150301B
86 s after the BAT trigger (Lien et al., GCN Circ. 17515). A fading
source consistent with the XRT position (Evans et al. GCN Circ. 17520)
and the optical transient reported by Buckley et al. (GCN Circ. 17518)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 05:56:39.89 = 89.16622 (deg.)
Dec (J2000) = -57:58:10.4 = -57.96955 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits for the White finding
chart and subsequent exposures 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_FC 86 236 147 16.2 +/- 0.1
white 3986 4121 133 >20.2
v 5833 6033 197 >19.7
b 3782 3982 197 >19.6
u 298 543 241 17.1 +/- 0.1
w1 6243 10068 579 >19.9
m2 6038 6237 197 >19.8
w2 5628 16054 963 >21.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).