TITLE:   GCN CIRCULAR
NUMBER:  20342
SUBJECT: GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC
DATE:    16/12/27 11:13:04 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), Z. Cano, L. Izzo, 
C. Thoene, R. Sanchez-Ramirez, K. Bensch (IAA-CSIC), D. A. Kann 
(IAA-CSIC, TLS), N. Tanvir (U. Leicester), S. Schulze, G. Leloudas 
(Weizmann Institute), S. Geier (IAC, GRANTECAN), A. Tejero 
(GRANTECAN) report on behalf of a larger collaboration:

We observed the optical counterpart of GRB 161219B (D’Ai et al. GCN 
20296) with OSIRIS at the 10.4m GTC telescope on La Palma (Spain). 
The observations consisted of 3 x 900 s spectra using grism R1000B, 
which covers the spectral region between 3700 and 7800 AA, plus g, r, i 
and z-band imaging. The point-like GRB counterpart is prominent on top 
of the elongated host galaxy.

The combined spectrum has mean UT epoch on 27.02 December (7.24 
days after the burst) and shows a strong continuum with clear broad 
features typical of a type Ic-BL supernova, implying that the supernova 
contribution is already significant. We also detect several emission 
features of the host galaxy (due to [OIII], [OII], [NII] and H) as well as CaII 
in absorption at the redshift of z = 0.1475 proposed for the GRB (Tanvir 
et al. GCN 20321).