2010CBET.2270....1M

G. H. Marion, Texas A&M University and University of Texas; J. Vinko, University of Szeged; and J. C. Wheeler, University of Texas, report that a spectrogram (range 430-1000 nm) of 2010cn (cf. CBET 2269), obtained on May 6.18 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by M. Shetrone, shows three broad, shallow features (at 484.6, 568.8, and 630.5 nm) superimposed on a blue continuum. The redshift, estimated from a narrow H-alpha emission line from the host galaxy, is 0.026. From the SuperNova IDentification code (Blondin and Tonry 2007, Ap.J. 666, 1024), the best-matching template is that of SN 2006aj, a broad-line type-Ic supernova, at five days before maximum light. Comparison with a library of supernovae spectra via the GELATO code (Harutyunyan et al. 2008, A.Ap. 488, 383) yields SN 1993J, a type-IIb supernova when close to maximum light, as the best-resembling spectrum.