TITLE: GCN CIRCULAR NUMBER: 26702 SUBJECT: LIGO/Virgo S200105ae: AT2020pp and AT2020py 10.4m GTC spectroscopy DATE: 20/01/11 11:34:38 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC A. F. Valeev (SAO-RAS), Y.-D. Hu, A. J. Castro-Tirado and E. Fernandez-Garcia (IAA-CSIC), V. Sokolov (SAO-RAS), I. Carrasco and A. Castellon (UMA), S. Anand (Caltech) and J. Font (GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report: Following the detection of AT2020pp/ZTF20aaervoa, and AT2020py/ZTF20aaerxsd (Stein et al. GCNC 26673) within the error area of the GW event S200105ae (LVC, GCNC 26640), we obtained optical spectra covering the range 3700-7400 A with the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) starting on Jan 10, 04:17 UT, under poor seeing conditions. For AT2020pp/ZTF20aaervoa, the GTC spectrum is consistent with a SN IIP at about 3 days after maximum at redshift z = 0.046 +/- 0.003, consistent with the redshift of the host galaxy derived from the emission lines (z = 0.0448 +/- 0.0005). For AT2020py/ZTF20aaerxsd, the GTC spectrum is consistent with a SN Ia  at about 3 days after maximum at redshift z = 0.055 +- 0.005, consistent with the redshift of the host galaxy derived from the emission lines (z =  0.0533 +/- 0.0005). Therefore we consider that neither AT2020pp/ZTF20aaervoa nor AT2020py/ZTF20aaerxsd are related to the S200105ae GW alert. This message can be quoted.