[vsnet-grb-info 18734] GRB 161117B: LCO optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20183
SUBJECT: GRB 161117B: LCO optical observations
DATE:    16/11/17 11:30:18 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi at fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi, I.A. Steele (LJMU), C.G. Mundell 
(U. Bath), A. Gomboc (U. Nova Gorica) on behalf of a large collaboration 
report:

One of the LCO 1-m telescope units in Siding Springs began observing 
Swift GRB 161117B (Troja et al., GCN 20182) in the SDSS r filter on 
November 17, 10:28:49 UT (39 minutes since the GRB trigger time). We do 
not find any object within the XRT error circle down to the following limit:

Mid time from GRB     Exposure     Filter       Magnitude
(min)                  (s)
----------------------------------------------------------
45                    5x120        SDSS-R       > 21.2
----------------------------------------------------------

Calibration is done against nearby USNOB-1 stars.