2005IAUC.8493....2M

M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics; and T. Matheson, National Optical Astronomy Observatory, report that a spectrum (range 350-740 nm) of SN 2005ar, obtained by J. Foster on Mar. 11.31 UT with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), reveals it to be a type-Ib supernova. The spectrum is very similar to spectra of SN 1998dt (Matheson et al. 2001, A.J. 121, 1648), around one week after maximum brightness, and exhibits He I (rest 587.6 nm) in absorption; however, the other He I lines (rest 667.8, 706.5 nm) are weak. Further spectroscopy is encouraged to check and monitor the evolution of the He I lines.