2012CBET.3304....2Z

T.-M. Zhang, National Astronomical Observatory of China (NAOC); and X.-F. Wang, Tsinghua Center for Astrophysics, Tsinghua University, Beijing, report that an optical spectrogram (range 400-8800 nm) of PSN J09240176+6833433 = SN 2012gn, obtained on Nov. 16.8 UT with the 2.16-m telescope (+ OMR) at Xinglong Station of the NAOC, shows the variable to be a type-II supernova. The spectrum is blue and relatively featureless, with a broad, low-contrast hydrogen balmer emission lines. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2012gn matches with SN 2004et at +2 days. Adopting a recession velocity 3968 km/s (after Falco et al. 1999, PASP 111, 438) for the host galaxy (UGC 4981), the photospheric expansion velocities, inferred from the absorption minima of H_alpha and H_beta, are about 9000 km/s.