Electronic Telegram No. 2009
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CBAT@CFA.HARVARD.EDU (science)
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SUPERNOVA 2009km
     S. Mattila, Tuorla Observatory; E. Kankare and P. A. Wilson, Nordic
Optical Telescope; and A. Pastorello, Queen's University, Belfast, report
that they obtained a low-resolution spectrum of 2009km (cf. CBET 1996) on
Nov. 7.0 UT with the Nordic Optical Telescope (+ ALFOSC; range 320-910 nm).
The spectrum of 2009km shows it to be a normal type-Ia supernova a few days
after maximum light.  Without an available host-galaxy redshift, they
used the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383) for
comparison of the observed spectrum with a library of supernova spectra to
estimate an approximate redshift for the supernova.  A host-galaxy
recessional velocity of about 5500 km/s was found to result in a close
match with the spectra of several normal type-Ia supernovae at a few days
after maximum light.  Adopting 5500 km/s as the recessional velocity, the
Si II 635.5-nm absorption minimum is measured to be blue-shifted by roughly
11000 km/s.  The measured R-band magnitude of 15.6 for 2009km corresponds
to an absolute magnitude of -18.9, assuming a distance of 79 Mpc (H_o =
70 km/s/Mpc).


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                         (C) Copyright 2009 CBAT
2009 November 9                  (CBET 2009)              Daniel W. E. Green