2010CBET.2373....1M

G. H. Marion, Harvard-Smithsonian Center for Astrophysics and University of Texas; J. Vinko, University of Szeged; and J. C. Wheeler, University of Texas, report that a spectrum (range 430-1000 nm) of 2010gd (cf. CBET 2368), obtained on July 14.3 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by S. C. Odewahn, shows prominent features of Mg II 448.1-nm, the "W"-shaped Fe II feature around 500 nm, Na D, Si II 635.5-nm, O I 777.4-nm, and the strong Ca II near-infrared triplet, characteristic of a type-Ic supernova near maximum brightness. No obvious He I, C II, or C I features could be identified. SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) shows a good match for templates from the normal type-Ic supernova 1994I at, or a few days before, maximum light. SNID also identifies possible fits to templates from type-Ia supernovae at about one week post- maximum, but photometry from CBET 2368 shows that 2010gd was still brightening on July 12. The redshift, estimated from a narrow H-alpha emission feature (due to imperfect host-galaxy subtraction) is 0.023, in agreement with that of the host galaxy, UGC 11064 (z = 0.0235; de Vaucouleurs et al. 1991, Third Reference Catalogue of Bright Galaxies, ver. 3.9). The expansion velocity, estimated from the Si II 635.5-nm feature, is 6100 km/s. This relatively low velocity also supports the type-Ic classification (e.g., Hunter et al. 2009, A.Ap. 508, 371).