2005IAUC.8553....2M

M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics, report that a spectrum (range 450-740 nm) of SN 2005cn (cf. IAUC 8549), obtained on June 28.21 UT by M. Calkins and R. Hutchins with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a type-Ia supernova with a spectral-feature age (Riess et al. 1997, A.J. 114, 722) of about 3 (± 2) days after maximum light; the supernova expansion velocity, derived from the minimum of Si II (rest 635.5 nm), and adopting the NED recession velocity of 2065 km/s for the host galaxy (from da Costa et al. 1998, A.J. 116, 1) is about 10000 km/s. A spectrogram of SN 2005cr (cf. IAUC 8552), obtained on June 28.19, shows it to be a type-Ia supernova, a few days before maximum light; the supernova expansion velocity, derived from the minimum of Si II (rest 635.5 nm), and adopting the NED recession velocity of 6437 km/s for the host galaxy (from Drinkwater et al. 1996, MNRAS 279, 595) is about 11000 km/s.