Electronic Telegram No. 1768
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 2009dc IN UGC 10064
     A. Harutyunyan, Telescopio Nazionale Galileo (TNG); N. Elias-Rosa,
Spitzer Science Center, California Institute of Technology; and S. Benetti,
Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova,
report that a spectrogram (range 330-770 nm, resolution 1.1 nm) of 2009dc
(cf. CBET 1762), obtained on Apr. 16.22 UT with the TNG (+ DOLORES), shows
it to be a type-Ia supernova before maximum light.  A comparison with the
spectra of SN 2006gz (Hicken et al. 2007, Ap.J. 669, L17) shows that 2009dc
reproduces well the same spectral features seen in the pre-maximum spectra
of SN 2006gz, including prominent C II lines and a blue continuum.
However, SN 2009dc shows a much-lower expansion velocity (about 8700 km/s,
as deduced from the Si II 635.5-nm absorption).


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2009 CBAT
2009 April 16                    (CBET 1768)              Daniel W. E. Green