2004IAUC.8440....2F

A. V. Filippenko and R. J. Foley, University of California, Berkeley, report that inspection of CCD spectra (range 320-730 nm), obtained by S. Mochnacki and J. Thomson (University of Toronto) on Nov. 15 UT with the 1.88-m reflector at David Dunlap Observatory, suggests that SN 2004fz (IAUC 8437) is of type Ia, roughly 1 week prior to maximum brightness. This classification was confirmed by inspection of higher-quality CCD spectra (range 310-710 nm) obtained by D. Kirkman and D. Tytler (University of California, San Diego) on Nov. 16 with the Shane 3-m reflector at Lick Observatory. Its spectral-feature age (Riess et al. 1997, A.J. 114, 722), derived from the Lick data, is 5 ± 2 days before maximum brightness. The expansion velocity of the ejecta, as measured from the minimum in the Si II 635.5-nm absorption trough, is about 11000 km/s. No interstellar Na I D absorption lines are present, to an equivalent width limit of about 0.02 nm.