[vsnet-grb-info 19608] GRB 170714A: Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21351
SUBJECT: GRB 170714A: Swift/UVOT Observations
DATE:    17/07/17 19:28:04 GMT
FROM:    Frank Marshall at GSFC  <femarsha at khamseen.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 170714A
384 s after the BAT trigger (D'Ai et al., GCN Circ. 21340).
There is weak evidence for a fading source consistent with the
position of the z-band afterglow candidate reported by
de Ugarte Postigo et al. (GCN Circ. 21346).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
v                  384         1695          175         >18.6
b                  496         1644          155         20.0 +/- 0.33
b                 5390        24672         1011         >20.3
u                  471         1619          284         20.1 +/- 0.35
u                 5185        30412         2351         20.4 +/- 0.18
u                81432        92912         1509         >20.7
w1                 446         1594          136         >21.0
m2                6006        29000         2637         >20.9
w2                5596        34449         3032         >22.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).