[IAUC] CBET 880: 20070312 : SUPERNOVA 2007ai IN MCG -04-38-4

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                                                  Electronic Telegram No. 880
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2007ai IN MCG -04-38-4
     N. Morrell and G. Folatelli, on behalf of the Carnegie Supernova
Project, report that a spectrum of 2007ai (cf. CBET 870), obtained on
Mar. 10.38 UT with the Baade 6.5-m telescope (+IMACS) at Las Campanas
Observatory, shows this to be a type-Ia supernova near maximum light.
Although the spectrum is noisy, it shows a blue continuum, and it
clearly shows features due to Si II and S II that are peculiar to
type-Ia supernovae.  Assuming the NED recession velocity of 9492 km/s
for the host galaxy (from Strauss et al. 1992, Ap.J. Suppl. 83, 29),
the 'superfit' spectrum-comparison code (Howell et al. 2005, Ap.J.
634, 1190) provides a good match to the spectrum of SN 1999ee at one
day before maximum light.  Under the same assumption, the maximum
absorption in the Si II 635.5-nm line indicates an expansion velocity
of about 10000 km/s.


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                         (C) Copyright 2007 CBAT
2007 March 12                    (CBET 880)               Daniel W. E. Green