2010CBET.2325....1C

P. Challis, R. J. Foley, R. Kirshner, E. Berger, A. Soderberg and G. H. Marion, Harvard-Smithsonian Center for Astrophysics, report that a CCD spectrum (range 345-865 nm), obtained on June 16 UT with the 6.5-m MMT telescope (+ Blue Channel), shows that 2010ed (cf. CBET 2324) is a type-Ia supernova. The continuum is relatively red, and there is a prominent (EW = 0.52 nm) Na D absorption component at the redshift of the host galaxy of cz = 14700 km/s. Cross-correlation with a library of supernova spectra, using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024), indicates that 2010ed may be similar to the luminous supernova 1999aa (e.g., Garavini et al. 2004, A.J. 128, 387) near maximum light. The Si II absorption is blueshifted by 10500 km/s. Given an apparent magnitude of about 18.7 (from CBET 2324), the distance modulus of 36.55 suggests that M = -17.85, which is quite dim for a luminous type-Ia supernova. Together with the strong D-line, this suggests a significant amount of extinction for SN 2010ed.