Electronic Telegram No. 2120
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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SUPERNOVAE 2009mx AND 2009my
     Rubab Khan, Ohio State University; and Jose Prieto, Carnegie
Observatories, report that optical spectra (range 390-740 nm; resolution 1.4
nm) of 2009mx and 2009my (cf. CBET 2095) were obtained with the Hiltner 2.4-m
telescope at MDM Observatory on Jan. 10.4 UT.  Cross-correlation with a
library of supernova spectra using SNID (Blondin and Tonry 2007, Ap.J. 666,
1024) showS that the spectrum of 2009mx is most similar to the subluminous
type-Ia supernova 1991bg at a couple weeks after maximum, and the spectrum
of 2009my is of an old type-II supernova.  After correcting the spectrum of
2009my for the recession velocity of its host galaxy (+3242 km/s; from de
Vaucouleurs et al. 1991, Third Reference Catalogue of Bright Galaxies, ver.
3), an expansion velocity of 7400 km/s is measured from the blue-shifted
absorption of the H-alpha profile.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 January 11                  (CBET 2120)              Daniel W. E. Green