2009CBET.1769....2A

J. Anderson and N. Morrell, on behalf of the Millenium Center for Supernova Science and the Carnegie Supernova Project collaboration, obtained spectroscopy (range 390-940 nm) of 2009dl and its host galaxy with the Magellan II Clay 6.5-m telescope (+ LDSS3) at Las Campanas Observatory on Apr. 17.2 UT. Inspection of the data reveals that 2009dl is a type-Ia supernova around maximum brigtness. From emission lines in the host-galaxy spectrum, they derive a redshift z = 0.1429 ± 0.0001. Adopting that redshift, the Si II 635.5-nm absorption in the supernova spectrum is blueshifted by roughly 9000 km/s. Cross-correlation with a library of supernova spectra via the "Supernova Identification" tool (Blondin and Tonry 2007, Ap.J. 666, 1024) provides excellent matches with a variety of normal type-Ia supernovae, between 5 days before and 5 days after maximum light.