2004IAUC.8457....3M

N. Morrell, G. Folatelli, M. Hamuy, and M. Roth, Carnegie Supernova Project, report that a CCD spectrogram of SN 2004gu (IAUC 8454), obtained on Dec. 19.33 UT with the 6.5-m Magellan II Clay Telescope (+ LDSS2) at Las Campanas, confirms this to be a type-Ia supernova. The spectrum strongly resembles that of SN 1999aa near maximum light except for the Ca II H and K absorption which is stronger in SN 2004gu. The expansion velocity inferred from the minimum of the Si II 635.5-nm absorption is 11600 km/s, assuming for the host galaxy a recession velocity of 13600 km/s (derived from the absorption lines present). The Si II 597.2-nm line is apparently absent, indicating a high-luminosity event.