GCN Circular 31855
Subject
GRB 220408A: Swift/UVOT Detection
Date
2022-04-08T15:34:23Z (2 years ago)
From
Samantha Oates at MSSL <samantha.oates@alumni.ucl.ac.uk>
S. R. Oates (U.Birmingham) and R. Caputo (GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220408A
112 s after the BAT trigger (Caputo et al., GCN Circ. 31848).
A source consistent with the XRT position (Beardmore et al., GCN Circ. 31852)
is detected in the initial white UVOT exposure only.
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white (FC) 112 262 147 20.30 +/- 0.22
white 605 799 40 >21.4
v 655 675 19 >19.3
b 581 774 39 >20.7
u 325 575 246 >20.2
w1 704 724 19 >17.9
m2 679 699 19 >17.4
w2 631 650 19 >17.7
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.042 in the direction of the burst
(Schlegel et al. 1998).