2010CBET.2218....2S

J. M. Silverman, I. K. W. Kleiser, A. J. L. Morton, and A. V. Filippenko, University of California, Berkeley, report that inspection of CCD spectra (range 340-1000 nm), obtained on Mar. 22 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that 2010av is likely a type-Ib/c supernova. Cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2010av is a few days past maximum light and that the most likely redshift is about 0.04. However, narrow emission lines from the host galaxy are present in the spectrum at redshift 0.029. SN 2010aw is a young type-II supernova; the H-alpha emission greatly dominates over the absorption component.