GCN Circular 35457
Subject
GRB 240101A: Swift/UVOT Upper Limits
Date
2024-01-02T12:10:21Z (9 months ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Via
email
N. P. M. Kuin (UCL-MSSL) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240101A
168 s after the BAT trigger (Cenko et al., GCN Circ. 35448).
No optical afterglow consistent with the BAT position
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 168 318 147 >20.4
white 168 1053 334 >20.8
v 656 4661 236 >18.7
b 582 773 39 >18.9
u 729 749 19 >18.3
w1 705 5071 236 >19.5
w2 804 824 19 >18.7
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.059 in the direction of the burst
(Schlegel et al. 1998).