TITLE: GCN CIRCULAR NUMBER: 24221 SUBJECT: LIGO/Virgo GW190425z: GTC spectroscopic classification of AT2019ebq/PS19qp DATE: 19/04/26 12:36:32 GMT FROM: Peter Jonker at SRON/RU Peter Jonker (SRON/RU), Daniel Mata-Sanchez (Manchester), Morgan Fraser (UCD), Pablo Rodríguez Gil (IAC), Kate Maguire (TCD), Andrew Levan (RU), Manuel Perez Torres (IAC), Danny Steeghs (Warwick), Stephen Smartt (Belfast), Nieves Castro (GTC) and Daniel Perez Valladares (GTC) report on behalf of the EMBOSS & ENGRAVE collaborations: We observed the candidate optical counterpart AT2019ebq (reported in GCN 24210) with the Gran Telescopio Canarias (GTC) at the Observatorio del Roque de los Muchachos on La Palma. We acquired one 1800 s spectrum using the R1000R grism beginning at 05:08:30 UT on 20190426. A preliminary host-subtracted spectrum shows broad absorption features unlike normal supernovae, with the most prominent centered at ~8600 Angstrom, making this target a prime candidate for the EM counterpart to GW190425.