2003IAUC.8129....3M

Matheson et al. add that a spectrum of SN 2003dt (cf. IAUC 8120), obtained as above on May 5.45 UT, shows it to be a type-Ia supernova several weeks past maximum. A spectrum of SN 2003dw (cf. IAUC 8124), obtained on May 5.34, shows it to be a type-Ia supernova near maximum. Adopting the NASA/IPAC Extragalactic Database recession velocity of 9003 km/s for the host galaxy, the supernova expansion velocity is 12500 km/s for Si II (rest 635.5 nm). The spectral-feature age of the supernova (Riess et al. 1997, A.J. 114, 722) is 1 ± 2 days after maximum light.