TITLE:   GCN CIRCULAR
NUMBER:  19420
SUBJECT: GRB 160509A: Further Swift/UVOT Observations
DATE:    16/05/10 21:30:27 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and T.G.R. Roegiers (PSU) report on behalf of the Swift/UVOT team:

The afterglow of the LAT-triggered GRB 160509A (Longo et al., GCN Circ. 19403)
has been detected in the X-ray (Kennea et al., GCN Circ. 19408),
optical (Levan et al., GCN Circ. 19410; Cenko et al., GCN Circ. 19416),
near-IR (Tanvir et al., GCN Circ. 19419), and radio (Alexander et al. GCN Circ. 19414) bands.
No afterglow was seen in the initial UVOT observation in the u filter
(Marshall and Roegiers, GCN Circ. 19412). As detailed in the table below,
additional UVOT observations also show no detections.
All the upper limits are at 2-sigma confidence.

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

u                7259        19794          626          >21.6
u               24201        36310         1802          >22.2
v               25452        36990         1257          >21.4
white           24826        36919         1802          >23.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.31 in the direction of the burst
(Schlegel et al. 1998).