[vsnet-grb-info 16644] GRB 150615A: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17925
SUBJECT: GRB 150615A: Swift/UVOT Detection
DATE:    15/06/15 13:44:32 GMT
FROM:    Samantha Oates at MSSL  <sro at mssl.ucl.ac.uk>

S. R. Oates (IAA-CSIC/UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150615A
122 s after the BAT trigger (Troja et al., GCN Circ. 17923).
A faint source consistent with the enhanced XRT position
(Beardmore et al. GCN Circ. 17924) is detected in the
combined white exposures.

Preliminary detection 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              122         1532          392         20.64 +/- 0.19
v                  611         1409           97        >18.3
b                  536         1507           97        >19.9
u                  280         1482          324        >20.2
w1                 660         1458           97        >19.2
m2                 635         1433           97        >18.9
w2                 586         1557          117        >19.4

The magnitudes in the table are not corrected for the significant Galactic
extinction due to the reddening of E(B-V) = 0.33 in the direction of the burst
(Schlegel et al. 1998).