2004IAUC.8403....2F

G. Folatelli, Las Campanas Observatory, together with M. Hamuy and N. Morrell, on behalf of the Carnegie Supernova Project, report that two optical spectra (range 400-730 nm) of SN 2004ef (cf. IAUC 8399), taken by W. Krzeminski on Sept. 7.16 UT with the Las Campanas 2.5-m du Pont telescope (+ Modular Spectrograph) and by J. Maza and E. Treister on Sept. 8.18 with the 6.5-m Clay telescope (+ Boller & Chivens Spectrograph), reveal that this is a type-Ia supernova, supported by the presence of Si II at 635.5, 413.0, and 597.2 nm and by S II at 545.4 and 564.0 nm. Similar spectral features have been observed in spectra of the normal type-Ia supernovae 1994D and 1999ee at 10 days before maximum, which suggests an early phase for 2004ef. The minimum of the Si II 635.5-nm line yields high expansion velocities of 16200 and 14500 km/s on each night, respectively, assuming the NED host-galaxy recession velocity of 9290 km/s. An upper limit of 0.05 nm is given to the equivalent width of the interstellar Na I D line, indicating a low reddening by dust in the host galaxy.