[vsnet-grb-info 25844] GRB 200613A: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27944
SUBJECT: GRB 200613A: Swift/UVOT Detection
DATE:    20/06/14 17:02:42 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall at milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC)
reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200613A
43621 s after the FERMI/LAT trigger (Ohno et al., GCN Circ. 27931).
A source consistent with the XRT position (Kennea et al., GCN Circ. 27936)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  10:12:10.03 = 153.04178 (deg.)
    Dec (J2000) = +45:45:14.1  =  45.75391 (deg.)
with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence).
This position is consistent with the optical counterparts
reported by Kann et al. (GCN Circ. 27935 & 27938) and
Pozanenko (GCN Circ. 27937).

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            44416        45204         775         19.65 +/- 0.07
v                45211        45427         213        >18.6
u                43621        44409         775         19.02 +/- 0.12

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).