GCN Circular 21846
Subject
GRB 170906B: Swift/UVOT Upper Limits
Date
2017-09-07T15:06:30Z (7 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
M. H. Siegel (PSU) and B. Sbarufatti (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170906B
81 s after the BAT trigger (Sbarufatti et al., GCN Circ. 21822).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 21823)
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 81 231 147 >20.2
u_FC 293 543 246 >19.3
white 81 930 243 >20.6
v 623 815 39 >17.5
b 548 741 39 >18.7
u 293 716 265 >19.3
w1 672 865 39 >18.4
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.42 in the direction of the burst
(Schlegel et al. 1998).