GCN Circular 34240
Subject
GRB 230723B: Swift/UVOT Upper Limits
Date
2023-07-23T21:12:26Z (a year ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230723B
3298 s after the BAT trigger (Page et al., GCN Circ. 34234).
No optical afterglow consistent with the XRT position (Page and Evans,
GCN Circ. 34238) 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 3298 3448 147 >20.6
white 3298 4680 344 >20.9
v 3456 3655 197 >19.1
b 4276 4475 197 >20.1
u 4070 4270 197 >20.0
w1 3866 4065 197 >19.3
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.411 in the direction of the burst
(Schlegel et al. 1998).