Electronic Telegram No. 1689
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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SUPERNOVAE 2009U, 2009W, AND 2009aa
     M. Stritzinger, N. Morrell, and G. Folatelli, on behalf of the Carnegie
Supernova Project and the Millennium Center for Supernova Studies, report that
they obtained spectra (range 380-940 nm) of supernovae 2009U, 2009W, and
2009aa on Feb. 8.1-8.2 UT with the 6.5-m Magellan II (Clay) telecope (+ LDSS3).
The spectrum of 2009U (cf. CBET 1679) reveals it to be a subluminous
1991bg-like type-Ia-supernova event at two to three weeks past maximum light.
     SN 2009W (cf. CBET 1683) appears to be a type-IIP supernova around a
month-and-a-half past explosion.  Cross correlation with a library of
supernovae spectra (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) reveals
that 2009W is most similar to supernova 2004dj at 51 days past explosion.
     A spectrum of 2009aa (cf. CBET 1685) appears to be that of a young
type-Ia supernova.  With the aid of SNID, they find an excellent match to SN
2002er at one week before maximum.  Adopting a host-galaxy recession velocity
of 8187 km/s (Theureau et al. 2007, A.Ap. 465, 71) for the host galaxy (ESO
570-G20), Si II is measured to be blue-shifted by roughly 10000 km/s.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2009 CBAT
2009 February 8                  (CBET 1689)              Daniel W. E. Green