[vsnet-grb-info 18721] GRB 161109A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20169
SUBJECT: GRB 161109A: Swift/UVOT Upper Limits
DATE:    16/11/11 15:34:35 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15 at ucl.ac.uk>

S. W. K Emery (MSSL-UCL) and A. D'Ai (INAF-IASFPA) report on behalf
of the Swift/UVOT team:

Swift-UVOT performed follow-up observations of the Fermi/LAT-detected
burst GRB 161109A (Desiante et al. GCN Circ. 20155) in a series of
observations tiled on the sky. Observations were taken in the u band
filter between T0+40.4 ks and T0+63.3 ks after the Fermi trigger.

Swift/UVOT did not find any new optical counterpart. The 3 sigma
upper limits at the position of each of the uncatalogued X-ray sources (Gibson et
al. GCN Circ. 20164) are:

Source  T_start (s)  T_end (s)  Exposure Time (s)  filter   3s UL

Source 2     40425     57980     1152     u     20.11
Source 3     40425     57980     1152     u     20.08 
Source 6     41245     63272     1121     u     19.22

The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.01 in the direction of
the burst (Schlegel et al. 1998).