[vsnet-grb-info 19036] GRB 170202A: LCO Sutherland observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20579
SUBJECT: GRB 170202A: LCO Sutherland observations
DATE:    17/02/02 22:32:33 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 170202A (Racusin et al. GCN 20575) on February 02, 
from 21:19 UT (2.8 hours since the GRB) with 1-m LCO telescope units in 
Sutherland with SDSS r and i filters. We detect the optical afterglow 
(Racusin et al. GCN 20575; Xi et al. GCN 20576; Lipunov et al. GCN 
20578) at the Swift-UVOT position with the following values:

Mid Time      Exposure       Filter       Magnitude (AB)
(hours)           (s)
-------------------------------------------------------
2.9             4x120         SDSS-R      19.65 +- 0.15
3.0             4x120         SDSS-I      19.32 +- 0.18
-------------------------------------------------------

as calibrated against nearby SDSS sources.