GCN Circular 27006

GRB 200205B: Swift/UVOT Detection

K. K. Simpson (PSU) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200205B
352 s after the BAT trigger (Evans et al., GCN Circ. 26993
Not found
 
 
).
A source consistent with the XRT position
(Evans et al. GCN Circ. 26993
Not found
 
 
)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  07:11:09.15 = 107.78812 (deg.)
    Dec (J2000) = -56:29:15.3  = -56.48759 (deg.)
with an estimated uncertainty of 0.42 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           6386           6586          196          18.92+-0.10
white           383            1042           478          16.81+-0.03
v                  540             733          38             16.88 +/-
0.17
b                  638            833           38             17.74 +/-
0.15
u                  614            808           38             17.25 +/-
0.16
w1                 589           783           38            16.88+-0.20
m2                 564          758           38             17.12 +/- 0.28
w2                 689          1056         46              >17.77

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.11 in the direction of the burst
(Schlegel et al. 1998).