[vsnet-grb-info 18508] GRB 160927A: TNG optical afterglow confirmation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19956
SUBJECT: GRB 160927A: TNG optical afterglow confirmation
DATE:    16/09/27 21:25:12 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo at brera.inaf.it>

P. D'Avanzo, A. Melandri (INAF-OAB), E. Palazzi (INAF-IASFBo), V. D'Elia (INAF/OAR & ASI/ASDC), 
L. Di Fabrizio, D. Carosati (INAF-TNG) report on behalf of the CIBO collaboration: 

We observed the field of the short GRB 160927A (Gibson et al., GCN 19952)
 with the 3.6m Telescopio Nazionale Galileo (TNG) equipped with DOLoRes. 
Observations were carried out in the r-sdss filter. Observations started on Sept 27 
at 20:12:49 UT (2.13 hours after the burst) and consist in a series of 5 images, 
each one lasting 180 seconds. 

At the enhanced XRT position (Evans, GCN 19953) in the co-added image we 
detect an object at the following coordinates (J2000):

RA, Dec = 17:04:58.22, +17:19:54.9

+/- 0.5". The object has a magnitude r = 22.6 +/- 0.1 (calibrated against nearby SDSS stars). 
This object is the same reported by Tkachenko et al. (GCN 19954). Given the mild evidence 
for fading, we propose this object as the optical afterglow of GRB 160927A.