GCN Circular 26502
Y.-D. Hu (IAA-CSIC), A. F. Valeev (SAO-RAS), A. J. Castro-Tirado and E. Fernandez-Garcia (IAA-CSIC), V. Sokolov (SAO-RAS), I. Carrasco and A. Castellon (UMA) and S. Geier (GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report: Following the detection of AT2019wmy/ZTF19acyiflj (Andreoni et al. GCNC 26416) within the error area of the GW event S191205ah (LVC, GCNC 26350), we obtained an optical spectrum covering the range 3700-7400 A with the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) on Dec 18. For AT2019wmy/ZTF19acyiflj, a magnitude r'= 19.79 +/- 0.05 at 06:35 UT is derived. The GTC spectrum is consistent with a SN Ia at redshift z = 0.081 +/- 0.003. Therefore we consider that AT2019wmy/ZTF19acyiflj is unrelated to the S191205ah GW alert.