LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc

We obtained an optical spectrum of the transient source DG19aqbkc/AT2019nqc (Andreoni et al. GCN 25362), identified as one possible electromagnetic counterpart of the the gravitational wave event S190814bv (LVC et al. GCN 25324, GCN 25333) by the DECam GROWTH team. The spectrum, obtained with the Robert Stobie spectrograph on the SALT telescope and the PG 300 grating, in the 3300-9800 Angstrom range with a 22 Angstrom spectral resolution, is consistent with a type II supernova two weeks after optical maximum. The redshift is approximately 0.077. The classification was obtained using SNID (Blondin & Tonry 2007). We measured a broad H-alpha line with a P-Cygni profile and an weak H-beta line in absorption. This result appears to rule out this transient as an optical counterpart of the gravitational wave event. [GCN OS NOTE(27aug19): Per author's request and administrator: The event reference was changed from "S190814b" to "S190814bv". And the SUBJECT-line was changed to "LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc", and the in-body TITLE- & SUBJECT-lines were removed.]