[vsnet-grb-info 18145] GRB 160625A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19593
SUBJECT: GRB 160625A: Swift/UVOT Upper Limits
DATE:    16/06/26 20:48:32 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale at ucl.ac.uk>

M. De Pasquale (UCL-MSSL) and A. Maselli (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160625A
7183 s after the BAT trigger (Maselli et al., GCN Circ. 19577).
No optical afterglow consistent with the XRT position
(Burrows et al. GCN Circ. 19578) is detected in the UVOT exposures.
We note the presence of a source approximately 3'' from the
XRT position. This source is present in the USNO catalogue.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the
exposures are:

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

white             7183         7952          344         >20.8
v                 8163         8363          197         >19.0
b                 7548         7747          197         >19.9
u                 7342         7542          197         >19.4
m2                8368         8483          113         >18.9
w2                7958         8158          197         >19.6

The magnitudes in the table are not corrected for the substantial Galactic
extinction due to the reddening of E(B-V) = 1.51 in the direction of the
burst (Schlegel et al. 1998).

-- 

Dr. Massimiliano De Pasquale
Research associate - Swift UVOT scientist
Mullard Space Science Laboratory, University College London