TITLE:   GCN CIRCULAR
NUMBER:  26428
SUBJECT: LIGO/Virgo S191213g: GRAWITA TNG classification of ZTF19acykzsk
DATE:    19/12/14 22:11:53 GMT
FROM:    Nancy Elias-Rosa at ICE-CSIC/IEEC  <eliasrosa.astro@gmail.com>

N. Elias-Rosa, S. Benetti (INAF-Padova), S. Piranomonte (INAF-OAR), A. Melandri (INAF-OABr), L. Di Fabrizio (TNG), on behalf of GRAWITA.

We report the classification of ZTF19acykzsk (Andreoni et al. GCNC 26424), transient candidate within the error area of the GW event S191213g (LVC, GCNC 26402). We obtained optical spectra covering the range 5000-9400 A with the 3.58m TNG telescope equipped with LRS at Observatorio del Roque de los Muchachos in La Palma (Spain) on Dec 14, 20:13 UT.

The spectrum is consistent with those of type II SN few days after explosion, at a z = 0.021, showing a blue continuum and prominent Halpha and HeI 587.6nm lines in emission. Halpha has a FWHM of about 11700km/s.

The classification was performed using the GELATO (Harutyunyan et al. 2008, A&A, 488, 383)
and SNID (Blondin and Tonry 2007, ApJ, 666, 1024) tools.