GCN Circular 18075
Subject
GRB 150724B: Swift/UVOT Detection
Event
Date
2015-07-27T17:25:04Z (10 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N.P.M. Kuin(MSSL/UCL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150724B
88.6ks after the LAT trigger (Bissaldi et al., GCN Circ. 18065),
which was also observed at high energy by Fermi-GBM (Veres et al.,
GCN Circ 18066) and Konus-Wind (Golenetskii et al. GCN Circ. 18074).
Five UVOT exposures were obtained of which the first two show a
weak detection at the XRT position (Osborne et al., GCN Circ. 18069).
Preliminary magnitudes and 3-sigma upper limits using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373)
are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 88619 88799 178 19.64+-0.12
white 88802 90608 1765 20.99+-0.14
white 90614 90748 60 >19.53
white 94379 94558 176 >20.82
white 94562 96236 1648 >22.01
The brightness is consistent with the RATIR observation at 147ks
in r and i (Butler et al, GCN 18072).
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).