[vsnet-grb-info 17543] GRB 160131A: Optical observations from T150 OSN

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18973
SUBJECT: GRB 160131A: Optical observations from T150 OSN
DATE:    16/02/02 15:12:35 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte at iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
V. Casanova (IAA-CSIC) and F. Aceituno (IAA-CSIC) report:

We observed the afterglow of GRB 160131A (Page et al. GCN 18951) 
from the 1.5m telescope (T150), at Sierra Nevada Observatory (Granada, 
Spain) in two epochs on the first and second night after the GRB.

In the first epoch we performed observations in the V, R and I filters 
and the object is well detected in all bands. During these observations
on January 31.807 (10.8 hr after the burst), the object has a magnitude of
R=17.90+/-0.02 (Vega), using as reference star the same 
USNO-B1.0 object mentioned in the circular by Xin et al. (GCN 18954).

On the second night we performed photometry in 5 bands, U, B, V, R 
and I, the object is again detected in all bands. In an image with mean 
epoch February 1.835 (35.5 hr after the burst) we detect the object at 
R=19.83+/-0.03.