TITLE: GCN CIRCULAR NUMBER: 25733 SUBJECT: LIGO/Virgo S190910h: WHT spectroscopy of AT2019pyz/PS19fbi DATE: 19/09/12 11:27:30 GMT FROM: Kate Maguire at Trinity College Dublin K. Maguire (TCD), S. Smartt (QUB), P. Jonker (SRON/Radboud Univ.), G. Cannizzaro (SRON/Radboud Univ.), I. Pastor-Marazuela (API/ASTRON), M. Fraser (UCD), A. Levan (Radboud Univ.), M. Perez-Torres (IAC), S. Srivastav (QUB) report on behalf of the GW@WHT collaboration: We obtained an optical spectrum of AT2019pyz/PS19fbi (TNS Astronote 2019-92) an optical transient within the sky localisation of the gravitational wave trigger S190910h (GCN 25707) with the ACAM instrument mounted on the William Herschel Telescope located at the Roque de Los Muchachos Observatory, La Palma, Spain on 20190912 02:35 UT. Using the supernova template matching code SNID (Blondin and Tonry, 2007), we find a good match with the Type Iax SN 2005hk at -4 days from peak at the redshift of the host galaxy of 0.038. We conclude that AT2019pyz is unrelated to the GW event S190910h.