[vsnet-grb-info 22716] GRB 190613A: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24815
SUBJECT: GRB 190613A: Swift/UVOT Detection
DATE:    19/06/13 17:36:46 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall at milkyway.gsfc.nasa.gov>

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

The Swift/UVOT began settled observations of the field of GRB 190613A
145 s after the BAT trigger (Ambrosi et al., GCN Circ. 24798).
A source consistent with the enhanced XRT position
(Osborne et al. GCN Circ. 24809)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  12:10:07.01 = 182.52920 (deg.)
    Dec (J2000) = +67:14:07.0  =  67.23529 (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              145          295          147         17.88 +/- 0.04
v                  634         1061           58         18.63 +/- 0.29
b                  560          753           39         18.93 +/- 0.21
u                  303          553          246         18.88 +/- 0.11
w1                 685        11118         1121        >20.1
m2                5323         6859          296        >20.8
w2                4913         6548          393        >21.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).