GCN Circular 32488

Subject

GRB 220826A: Swift/UVOT Detection

Event

GRB 220826A

Date

2022-08-26T18:47:37Z (3 years ago)

From

Paul Kuin at MSSL <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and R. Caputo (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220826A
91 s after the BAT trigger (Caputo et al., GCN Circ. 32484Loading...
 
 ).
A source consistent with the XRT position (Beardmore et al. GCN Circ. 32485Loading...
 
 )
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  13:45:38.51 = 206.41047 (deg.)
    Dec (J2000) = -44:02:19.2  = -44.03866 (deg.)
with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence).

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               91          240          147         18.12 +/- 0.05
v                  632          827           39        >18.4
b                  559          753           39        >18.6
u                  303          553          246         18.69 +/- 0.13
w1                 682          702           19        >17.7
m2                 831          851           19        >17.8
w2                 608          802           39        >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.110 in the direction of the burst
(Schlegel et al. 1998).