Electronic Telegram No. 955
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 2007cb IN ESO 510-G31
     N. Morrell, on behalf of the Carnegie Supernova Project, reports
that a spectroscopic observation (range 350-960 nm) of 2007cb (cf.
CBET 949), obtained on May 8.27 UT with the Magellan I Walter Baade
telescope (+ IMACS) at Las Campanas Observatory, shows this to be a
type-Ia supernova about 2 weeks past maximum light.  Adopting for the
parent galaxy the NED recession velocity of 10923 km/s (Jones et al.
2004, "6dF Galaxy Survey Data Release 1"), the minimum of the Si II
635.5-nm absorption yields an expansion velocity of 10500 km/s.  The
'superfit' spectrum-comparison code (Howell et al. 2005, Ap.J. 634,
1190) provides an excellent match with the spectrum of SN 1999aa at
an age of 14 days after maximum light.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 May 10                      (CBET 955)               Daniel W. E. Green