2010CBET.2221....1S

M. Stritzinger, J. L. Prieto, and N. Morrell, Carnegie Observatories; G. Folatelli, Universidad de Chile; and G. Pignata, Universidad Andres Bello, on behalf of the Carnegie Supernova Project and the Millennium Center for Supernova Science, communicate that they obtained optical spectra of 2010as (cf. CBET 2215) on Mar. 20.1 and 22.1 UT with the Du Pont telescope (+ WFCCD), and on Mar. 21.1 with the Gemini-South telescope (+ GMOS). The spectra suggest that this object is a young type-Ib/c supernova, resembling supernova 2007Y (Stritzinger et al. 2009, Ap.J. 696, 713) at two weeks before maximum. The spectra exhibit a number of strong and shallow features. Prevalent P-Cyg absorption lines are present at 620 and 820 nm, which are attributed to H-alpha and the Ca II triplet, respectively. Adopting a host-galaxy recession velocity of 2193 km/s (Theureau et al. 1998, A.Ap. Suppl. 130, 333) for the host galaxy (NGC 6000), H_alpha and the Ca II triplet are measured to be blue-shifted in the first spectrum by roughly 16700 and 15600 km/s, respectively. Strong multi-component Na I D interstellar absorption lines are present in the spectra, indicative that this supernova suffers considerable reddening.