2009CBET.1787....1S

M. Stritzinger and N. Morrell, Las Campanas Observatory; and J. Anderson, University of Chile, on behalf of the Carnegie Supernova Project and the Millennium Center for Supernova Science, report that they obtained optical spectra of 2009ca (cf. CBET 1750) on Apr. 7.1, 17.1, and 22.1 UT with the Magellan BAADE (+ IMACS), Magellan CLAY (+ LDSS3), and du Pont (+ B&C) telescopes, showing that 2009ca appears to resemble a type-Ic supernova. They find the initial spectrum of 2009ca to be similar, but not identical, to that of SN 2004aw (Taubenberger et al. 2006, MNRAS 371, 1459) a few days past maximum. The Fe II multiplet 42 lines (rest 492.4, 501.8, and 516.9 nm) are prevalent and narrow. Adopting a host-galaxy recession velocity, determined with the "Supernova Identification" code (Blondin and Tonry 2007, Ap.J. 666, 1024), of 26981 km/s, they find the Fe II multiplet 42 lines to be blue- shifted by roughly 13000 km/s. The subsequent spectra resemble supernovae 1983V and 2004aw at a couple of weeks past maximum, and the Fe II lines appear to be blue-shifted by roughly 11000 km/s.