[vsnet-grb-info 20118] GRB 171209A: LCO 1-m telescope observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22214
SUBJECT: GRB 171209A: LCO 1-m telescope observations
DATE:    17/12/09 18:11:27 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi at fe.infn.it>

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

We observed Swift GRB171209A (LaPorte et al. GCN 22213) on December 9, 
16:25 UT (1.65 hours post burst) with one of the 1-m LCO telescopes in 
Siding Springs in the SDSS ri filters. We detect the UVOT candidate, 
which is not visible in archival Pan-STARRS images, with the following 
magnitudes:

Mid Time     Exposure        Filter     Magnitude (AB)
(hr)           (s)
------------------------------------------------------
1.69          2x120          SDSS-R       18.2 +- 0.3
1.78          2x120          SDSS-I       17.8 +- 0.3
------------------------------------------------------

as calibrated against nearby Pan-STARRS objects. Due to the vicinity of 
(~4") of a bright object, our estimated magnitudes are to be taken 
cautiously.