[vsnet-grb-info 16683] GRB 150626A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17964
SUBJECT: GRB 150626A: Swift/UVOT Upper Limits
DATE:    15/06/26 13:57:17 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale at ucl.ac.uk>

M. De Pasquale (UCL-MSSL) and T. Roegiers (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150626A
98 s after the BAT trigger (Roegiers et al., GCN Circ. 17960).
No optical afterglow consistent with the XRT position (Evans
GCN Circ. 17961) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposures and subsequent exposures are:

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

white_FC            98          248          147         >20.4
u_FC               311          561          246         >19.6

white               98         1540          392         >21.1
u                  311         1490          324         >19.8
v                  641         1590           95         >18.8
b                  566         1514           97         >19.7
uw1                690         1465           78         >18.8
um2                665         1440           97         >18.6
uw2                616         1390           97         >19.0

The magnitudes in the table are not corrected for the substantial
Galactic extinction due to the reddening of E(B-V) = 0.37 in the
direction of the burst (Schlegel et al. 1998).