[vsnet-grb-info 23382] LIGO/Virgo S190814b

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25481
SUBJECT: LIGO/Virgo S190814b
DATE:    19/08/26 20:23:14 GMT
FROM:    Marina Orio at INAF-Padova and U of Wisconsin  <orio at astro.wisc.edu>

TITLE: LIGO/Virgo S190814b
SUBJECT: SALT optical spectrum of candidate DG19aqbkc

David Buckley, (South Africa Astronomical Observatory, South Africa),  Stefano Ciroi (University of Padova, Department of Physics and Astronomy, Italy),  Mariusz Gromadzski (University of Warsaw, Astronomical Observatory, Poland), Mansi Kasliwal (Cahill Center for Astronomy and Astrophysics, Caltech, Pasadena, CA, USA), Marina Orio (INAF-Padova Observatory, Italy, and Department of Astronomy, University of Wisconsin-Madison, USA), Jeff Cooke (Australian Research Council Center of Exellence for Gravitational Wave Discovery,  Swinburne University of Technology, Australia) , Saurabh Jha (Department of Physics and Astronomy, Rutgers University, NJ, USA) and  Moses Mogotsi (SALT, South Africa Astronomical Observatory, South Africa), report:

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.