2009CBET.1756....1K

K. Konishi, Y. Ihara, and K. Tokita, University of Tokyo; N. Morimoto, Tohoku University; and T. Hattori, National Astronomical Observatory of Japan, report that a spectrogram (range 370-900 nm) of 2009by (cf. CBET 1748), obtained on Apr. 4.28 UT with the 8.2-m SUBARU Telescope (+ FOCAS), shows it to be a type-II supernova. Their recently-developed identification code suggests that the spectrum is best fitted to that of the type-IIP supernova 1999em at five days after the explosion (Elmhamdi et al. 2003, MNRAS 338, 938). There are narrow emission-line components of H_alpha and H_beta, corresponding to z = 0.021 ± 0.001; it is unclear whether these narrow components originate from the H II region of the host galaxy or are intrinsic to the supernova. Thus, it the possibility cannot be excluded that this supernova is of type IIn.