2005CBET..324....1M

M. Modjaz, S. Blondin, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics, report that a spectrum (range 450-740 nm) of SN 2005ls (cf. IAUC 8643), obtained on Dec. 21.21 UT by M. Calkins with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a type-Ia supernova, with a spectral-feature age (Riess et al. 1997, A.J. 114, 722) of about 8 (± 2) days after maximum light. Adopting a recession velocity of 6331 km/s for the host galaxy (Falco et al. 1999, PASP 111, 438), the maximum absorption in the Si II line (rest 635.5 nm) is blueshifted by 11000 km/s. Interstellar Na I D absorption at the redshift of the host galaxy is visible in the spectrum with an equivalent width of 0.2 nm.