[vsnet-grb-info 22718] GRB 190613B: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24817
SUBJECT: GRB 190613B: Swift/UVOT Detection
DATE:    19/06/13 17:39:39 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall at milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190613B
106 s after the BAT trigger (D'Ai et al., GCN Circ. 24807).
A source consistent with the enhanced XRT position
(Beardmore et al. GCN Circ. 24812)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  20:21:43.66 = 305.43191 (deg.)
    Dec (J2000) = -04:38:48.0  =  -4.64666 (deg.)
with an estimated uncertainty of 0.43 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              106          256          147         17.84 +/- 0.04
v                  648          667           19        >18.0
b                  574          594           19        >18.7
u                  318          568          246         18.86 +/- 0.12
w1                 697          717           19        >18.6
m2                 672          692           19        >18.4
w2                 624          643           19        >18.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).