GCN Circular 18092
Subject
GRB 150728A: Swift/UVOT Upper Limits
Event
Date
2015-07-28T21:08:25Z (11 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and H. A. Krimm (CRESST/GSFC/USRA) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150728A 75
s after the BAT trigger (Krimm et al., GCN Circ. 18087).
No optical afterglow consistent with the XRT position (Beardmore et al.
GCN Circ. 18088) or the Faulkes position (Dichiara et al. GCN Circ.
18090) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding
chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 75 225 147 >21.3
u_FC 288 537 246 >20.4
white 75 6991 730 >22.0
v 617 5982 275 >19.8
b 543 6803 452 >21.1
u 288 6597 678 >21.0
w1 668 6392 452 >20.4
m2 643 6187 452 >20.2
w2 593 5777 255 >20.1
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.20 in the direction of the
burst (Schlegel et al. 1998).