GCN Circular 13829
Subject
GRB 120927A: Swift/UVOT Upper Limits
Event
Date
2012-09-29T15:02:02Z (14 years ago)
From
Stefan Immler at NASA/GSFC <stefan.m.immler@nasa.gov>
S. Immler (NASA/CRESST/GSFC) and A. Maselli (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 120927A
158 s after the BAT trigger (Maselli et al., GCN Circ. 13822).
No optical afterglow consistent with the enhanced XRT position
(Beardmore et al. GCN Circ. 13824) 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) and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 158 308 147 >20.3
u_FC 317 567 246 >19.5
white 158 6331 580 >21.0
v 648 6625 317 >19.1
b 572 6127 432 >20.1
u 317 5921 659 >20.2
w1 697 5717 413 >19.6
m2 672 5511 225 >19.6
w2 623 6537 432 >20.3
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).