GCN Circular 37296
Subject
GRB 240825A: Swift/UVOT Detection
Date
2024-08-26T12:54:52Z (a month ago)
Edited On
2024-08-26T13:40:13Z (a month ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Rahul Gupta at NASA GSFC <rahulbhu.c157@gmail.com>
Via
email
N. P. M. Kuin (UCL-MSSL) and R. Gupta (NASA GSFC)
report on behalf of the Swift/UVOT team:The Swift/UVOT began settled
observations of the field of
GRB 240825A 93 s after the BAT trigger (Gupta et al.,
GCN Circ. 37274). A source consistent with the XRT
position (Evans et al. GCN Circ. 37290 is detected
in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 22:58:17.26 = 344.57192 (deg.)
Dec (J2000) = +01:01:36.9 = 1.02691 (deg.)
with an estimated uncertainty of 0.42 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 93 243 147 15.58 +/- 0.02
v 807 827 20 17.02 +/- 0.20
b 561 580 20 17.54 +/- 0.15
u 305 555 246 16.93 +/- 0.05
w1 684 1281 58 18.55 +/- 0.30
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.063 in the direction of the burst
(Schlegel et al. 1998).