TITLE: GCN CIRCULAR NUMBER: 26703 SUBJECT: LIGO/Virgo S200105ae: AT2020pq, AT2020ps and AT2020pv 10.4m GTC spectroscopy DATE: 20/01/11 13:33:33 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC A. J. Castro-Tirado (IAA-CSIC), A. F. Valeev (SAO-RAS), Y.-D. Hu and E. Fernandez-Garcia (IAA-CSIC), V. Sokolov (SAO-RAS), R. Sanchez-Ramirez (INAF-IAPS) and J. Font (GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report: Following the detection of AT2020pq/ZTF20aaervyn, AT2020ps/ZTF20aaerqbx and AT2020pv/ZTF20aaertpj (Stein et al. GCNC 26673) within the error area of the GW event S200105ae (LVC, GCNC 26640), we obtained optical spectroscopy covering the range 3700-7400 A with the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) starting on Jan 11, 06:03 UT. For AT2020pq/ZTF20aaervyn, the GTC spectrum is consistent with a SN Ia close to maximum, at redshift z = 0.112 +/- 0.004, consistent with the redshift of the host galaxy derived from the emission lines (z = 0.1146 +/- 0.0005). For AT2020ps/ZTF20aaerqbx, the GTC spectrum is consistent with a SN IIp about 5 days prior to maximum at redshift z = 0.098 +/- 0.016, consistent with the redshift of the host galaxy derived from the emission lines (z = 0.0780 +/- 0.0005). For AT2020pv/ZTF20aaertpj, the GTC spectrum is consistent with a SN Ib close to maximum at redshift z = 0.026 +/- 0.006, consistent with the redshift of the host galaxy derived from the emission lines (z = 0.0280 ± 0.0005). Therefore we consider that AT2020pq/ZTF20aaervyn, AT2020ps/ZTF20aaerqbx and AT2020pv/ZTF20aaertpj are unrelated to the S200105ae GW alert. This message can be quoted.