Electronic Telegram No. 455
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
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SUPERNOVA 2006bf IN UGC 8093
     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_vs_sn2000H.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.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2006 CBAT
2006 April 1                     (CBET 455)               Daniel W. E. Green