GCN Circular 34446
Subject
GRB230815A: Swift/UVOT upper limits
Date
2023-08-16T12:42:08Z (9 months ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
Via
email
A. A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230815A 155 s after the BAT trigger (Klingler et al., GCN Circ. 34434).
No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 34437) 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 summed exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 155 305 147 >20.1
white 513 1531 242 >20.3
v 390 1582 136 >18.5
b 489 1506 114 >19.3
u 464 6300 293 >19.4
uvw1 439 1632 136 >18.6
uvm2 761 1606 97 >18.3
uvw2 365 1557 136 >18.8
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.73 in the direction of the burst (Schlegel et al. 1998).