2010CBET.2278....1H

E. Y. Hsiao, N. Suzuki, AND P. E. Nugent, Lawrence Berkeley National Laboratory; Janos Botyanszki and Joshua Meyers, University of California, Berkeley; and D. D. Balam, Dominion Astrophysical Observatory, National Research Council of Canada (NRCC), report that inspection of a low-signal- to-noise-ratio CCD spectrum (range 330-980 nm), obtained on May 8.46 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that 2010ck (cf. CBET 2263) is a type-II supernova. The spectrum was taken nearly two weeks past the discovery date. The supernova sustained the initially reported brightness – measured to have a magnitude V = 16.77 and color B-V = +0.70 on May 11.33 UT with the 1.82-m Plaskett Telescope of the NRCC. The "superfit" software of Howell et al. (2005, Ap.J. 634, 1190) identified the spectrum as that of a young type-II supernova at z = 0.027, which matches the redshift of the reported host galaxy, MCG +06-31-61. The spectrum closely resembles that of SN 1999em, with the H-alpha and H-beta features visible but still weak.