[IAUC] CBET 2373: 20100715 : SUPERNOVA 2010gd IN UGC 11064

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                                                  Electronic Telegram No. 2373
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Room 209; Dept. of Earth and Planetary
 Sciences; Harvard University; 20 Oxford St.; Cambridge, MA  02138; U.S.A.
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SUPERNOVA 2010gd IN UGC 11064
     G. H. Marion, Harvard-Smithsonian Center for Astrophysics and University
of Texas; J. Vinko, University of Szeged; and J. C. Wheeler, University of
Texas, report that a spectrum (range 430-1000 nm) of 2010gd (cf. CBET 2368),
obtained on July 14.3 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario
Low-Resolution Spectrograph) by S. C. Odewahn, shows prominent features of
Mg II 448.1-nm, the "W"-shaped Fe II feature around 500 nm, Na D, Si II
635.5-nm, O I 777.4-nm, and the strong Ca II near-infrared triplet,
characteristic of a type-Ic supernova near maximum brightness.  No obvious
He I, C II, or C I features could be identified.  SNID (Blondin and Tonry 2007,
Ap.J. 666, 1024) shows a good match for templates from the normal type-Ic
supernova 1994I at, or a few days before, maximum light.  SNID also identifies
possible fits to templates from type-Ia supernovae at about one week post-
maximum, but photometry from CBET 2368 shows that 2010gd was still brightening
on July 12.  The redshift, estimated from a narrow H-alpha emission feature
(due to imperfect host-galaxy subtraction) is 0.023, in agreement with that of
the host galaxy, UGC 11064 (z = 0.0235; de Vaucouleurs et al. 1991, Third
Reference Catalogue of Bright Galaxies, ver. 3.9).  The expansion velocity,
estimated from the Si II 635.5-nm feature, is 6100 km/s.  This relatively low
velocity also supports the type-Ic classification (e.g., Hunter et al. 2009,
A.Ap. 508, 371).


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                         (C) Copyright 2010 CBAT
2010 July 15                     (CBET 2373)              Daniel W. E. Green