[vsnet-grb-info 19216] GRB 170317A: LCO FTN observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20901
SUBJECT: GRB 170317A: LCO FTN observations
DATE:    17/03/18 09:56:26 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi at fe.infn.it>

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

We observed Swift GRB 170317A (LaPorte et al. GCN 20885) on March 18, 
06:01 UT (0.84 days since the GRB) with the 2-m LCO Faulkes Telescope 
North with SDSS r and i filters. We marginally detect the optical 
afterglow (LaPorte et al.; Mazaeva et al. GCN 20886, 20893; Xin et al. 
GCN 20888; Mao et al. GCN 20889, 20890; Kuin et al. GCN 20894) in the r 
filter with the following values:

Mid Time      Exposure       Filter       Magnitude (AB)
(days)           (s)
-------------------------------------------------------
0.87          10x120          SDSS-R        22.9 +- 0.3
0.88          10x120          SDSS-I        > 22.0
-------------------------------------------------------

as calibrated against nearby PanSTARRS-1 DR1 objects.