2010CBET.2580....1F

R. J. Foley, R. Chornock, N. Sanders, and I. Czekala, Harvard-Smithsonian Center for Astrophysics, on behalf of a larger collaboration, report that a spectrum (range 320-830 nm), obtained on Dec. 9.06 UT with the Blue Channel Spectrograph on the 6.5-m MMT telescope, shows that 2010kh (cf. CBET 2562) is a type-IIb supernova. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that the best fit for 2010kh is to the spectrum of the type- IIb supernova 1993J at a phase of 3-7 days after maximum brightness. The absorption minimum of H-alpha is blueshifted by 14600 km/s.