2010CBET.2149....1M

S. Mattila, Tuorla Observatory; E. Kankare and J. Datson, Nordic Optical Telescope; and A. Pastorello, Queen's University, Belfast, report that they obtained low-resolution spectra of 2010O (cf. CBET 2144) and 2010P (cf. CBET 2145) on Jan. 28.0 UT with the Nordic Optical Telescope (+ ALFOSC; ranges 380-690 nm and 320-910 nm, respectively). The spectrum of 2010O shows it to be a type-Ib supernova close to maximum light. The presence of prominent narrow Na I D (588.995, 589.592 nm) absorption lines from the host galaxy indicates a significant reddening of E(B-V) about 0.6, according to the relation of Turatto et al. (2002, http://lanl.arxiv.org/abs/astro-ph/0211219). Comparison of the dereddened spectrum of 2010O with a library of supernova spectra using the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383) yields a best match with the spectra of the type-Ib/c supernova 2002ji and the type-Ib supernova 2005bf around maximum light. The low-signal-to-noise spectrum of 2010P shows an extremely red continuum that is a signature of a high extinction (cf. CBET 2145); no clear spectral lines are visible, with the exception of the Ca II infrared triplet that confirms the supernova nature of 2010P.