Electronic Telegram No. 2117
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 2010B IN NGC 5370
     K. Kinugasa, H. Takahashi, S. Honda, H. Taguchi, and O. Hashimoto,
Gunma Astronomical Observatory (GAO), write that a low-resolution spectrum
(range 420-800 nm; resolution about 500) of 2010B (cf. CBET 2115), was
obtained on Jan. 9.7 UT with the GAO 1.5-m telescope (+ GLOWS).  The spectrum
shows it to be a type-Ia supernova before maximum light.  Adopting the NED
recession velocity of 3057 km/s for NGC 5370 (de Vaucouleurs et al. 1991,
Third Reference Catalogue of Bright Galaxies, ver. 3.9), the expansion
velocity derived from the Si II absorption minimum (rest 635.5 nm) is about
10000 km/s.  Comparison with a library of spectra via the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024)
indicates that 2010B is most similar to SN 2002bo at about four days before
maximum.


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                         (C) Copyright 2010 CBAT
2010 January 10                  (CBET 2117)              Daniel W. E. Green