Electronic Telegram No. 699
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 2006lc IN NGC 7364
     S. Blondin, M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian
Center for Astrophysics, report that a spectrum (range 350-740 nm) of 2006lc
(cf. CBET 693), obtained on Oct. 26.19 UT by M. Calkins with the F. L.
Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a type-Ib/c
supernova around maximum light.  The spectrum exhibits conspicuous lines of
He I (rest 447.1, 587.6, 667.8 nm), as well as a strong absorption near 620
nm due to Si II (rest 635.5 nm).  Cross-correlation with a library of
supernova spectra shows that 2006lc is most similar to the type-Ib supernova
2005hg (cf. CBET 271) at -2 days from maximum light, and to the type-Ib/c
supernova 1999ex (see Hamuy et al. 2002, A.J. 124, 417) at maximum.  SN
2006lc is thus an example of an intermediate case between supernova types Ib
and Ic.  A comparison plot can be seen at the following URL:
http://cfa-www.harvard.edu/oir/Research/supernova/spectra/sn2006lc_comp.gif.
Adopting a recession velocity of 4894 km/s (from Falco et al. 2000,
"The Updated Zwicky Catalogue", vol. 1), the maximum absorption in the Si
II (rest 635.5 nm) line is blueshifted by roughly 7400 km/s.


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                         (C) Copyright 2006 CBAT
2006 October 27                  (CBET 699)               Daniel W. E. Green