2006CBET..455....1B

S. Blondin, 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 2006bf (cf. IAUC 8693), obtained on Mar. 31.36 UT by H. Hao with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), shows thisobject to be a reddened type-Ib/IIb supernova. The spectrum is dominated by P-Cyg profiles of He I lines, with a strong absorption near 640 nm possibly due to H_alpha. Cross-correlation with a library of supernova spectra indicates that SN 2006bf is similar to SN 2000H (cf. IAUC 7361) at +12 days from maximum light, at an approximate redshift of z = 0.033 ± 0.010 (cz = 9900 ± 3000 km/s, slightly higher than the recession velocity of its host galaxy UGC 8093, which has cz = 7115 km/s; cf. 'The Updated Zwicky Catalog', http://tdc-www.harvard.edu/uzc/). SN 2000H was originally classified as a type-Ia supernova (cf. IAUC 7366), then as a type-Ic event (cf. IAUC 7367), and finally as a "type-IIb" event (cf. IAUC 7375). A comparison between these two supernovae can be seen at the following URL: http://cfa-www.harvard.edu/oir/Research/supernova/spectra/ sn2006bf_vssn2000H.ps.gif. Adopting 7115 km/s for the recession velocity of the supernova, the maximum absorptions in the He I lines at 587.6 and 706.5 nm are blueshifted by roughly 8500 km/s. If the prominent absorption trough around 640 nm is assumed to be due to H_alpha, the maximum absorption in this line is blueshifted by 11500 km/s.