Supernova 2004ex in NGC 182

A. Harutyunyan, M. Turatto, S. Benetti, G. Blanc, H. Navasardyan, and L.

Zampieri, Osservatorio Astronomico di Padova; and A. Pastorello, Max

Planck Institut, report that inspection of a spectrogram of SN 2004ex

(cf. IAUCs 8418, 8420), obtained on Nov. 16.97 UT with the Asiago 1.8-m

telescope (+ AFOSC; range 355-780 nm, resolution 2.4 nm), shows prominent

587.6-, 667.8-, and 706.5-nm He I lines and relatively faint H_alpha, all

with P-Cyg profiles. The spectrum closely resembles that of SN 1993J at

41 days after explosion (Barbon et al. 1995, A.Ap. Suppl. 110, 513),

however, with a much fainter H_alpha emission. The expansion velocity,

deduced from the H_alpha-emission minimum, is still very high (about

10600 km/s). This therefore redefines the spectroscopic classification

of SN 2004ex as type IIb.