Electronic Telegram No. 1688
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 2009Y IN NGC 5728
     K. Kinugasa and S. Honda, Gunma Astronomical Observatory (GAO); and
H. Yamaoka, Kyushu University, write that a low-resolution spectrogram
(range 410-800 nm, resolution about 500) of 2009Y (cf. CBET 1684), was
obtained on Feb. 6.7 UT with the GAO 1.5-m telescope (+ GLOWS).  The
spectrum shows 2009Y to be a type-Ia supernova a few days before maximum
light.  Adopting the NED recession velocity of 2804 km/s for NGC 5728
(Catinella et al. 2005, A.J. 130, 1037), the expansion velocity derived
from the Si II absorption minimum (rest 635.5 nm) is about 17000 km/s.
     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 a spectrogram (range 380-940 nm) of 2009Y on Feb. 8.1-8.2 UT
with the 6.5-m Magellan II (Clay) telecope (+ LDSS3).  The spectrum of 2009Y
shows it to be a type-Ia supernova a few days before maximum.  With the use
of the SNID software, they find 2009Y to be most similar to SN 2002bo between
two and four days prior to maximum.  Adopting a host-galaxy recession velocity
of 2804 km/s (Catinella et al. 2005, A.J. 130, 1037) for the host galaxy
(NGC 5728), Si II is measured to be blue-shifted by roughly 16000 km/s.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2009 CBAT
2009 February 8                  (CBET 1688)              Daniel W. E. Green