[IAUC] CBET 1058: 20070911 : SUPERNOVAE 2007hu AND 2007hv

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                                                  Electronic Telegram No. 1058
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVAE 2007hu AND 2007hv
     S. Blondin, R. Kirshner, and P. Challis, Harvard-Smithsonian Center
for Astrophysics report that a spectrogram (range 350-740 nm) of 2007hu
(cf. CBET 1056), obtained by P. Berlind on Sept. 11.14 UT with the F. L.
Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a reddened
type-Ia supernova around maximum light.  Cross-correlation with a library
of supernova spectra indicates that 2007hu is most similar to the type-Ia
supernova 1999ej (cf. IAUC 7286, 7298) at one day before maximum.  Adopting
a recession velocity of 10637 km/s for the host galaxy (from The Updated
Zwicky Catalog, http://tdc-www.harvard.edu/uzc/), the maximum absorption
in the Si II line (rest 635.5 nm) is blueshifted by roughly 13500 km/s.
Also, interstellar Na I D absorption at the redshift of the host galaxy is
visible in the spectrum with an equivalent width of 0.6 nm.
     Blondin et al. add that a spectrum (range 350-740 nm) of 2007hv (cf.
CBET 1056), obtained as above on Sept. 11.45 by Berlind, shows it to be a
type-II supernova roughly 1-2 weeks past explosion.  The spectrum is
similar to that of the type-II-plateau supernova 1999em (cf. IAUC 7294,
7296) at 9 days past explosion.  Adopting a recession velocity of 5054 km/s
for the host galaxy (from de Vaucouleurs et al. 1991, Third Ref. Cat. of
Bright Galaxies), the maximum absorption in the H_alpha line (rest 656.3 nm)
is blueshifted by roughly 12000 km/s.


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                         (C) Copyright 2007 CBAT
2007 September 11                (CBET 1058)              Daniel W. E. Green