Electronic Telegram No. 1907
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)
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVAE 2009hr AND 2009hz
     C. Inserra, Istituto Nazionale di Astrofisica, Osservatorio Astronomico
di Catania; I. Agnoletto, Universita degli Studi di Padova; N. Elias-Rosa,
Spitzer Science Center, California Institute of Technology; and S. Benetti,
Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, report
that a spectrum of 2009hr (cf. CBET 1891) and a spectrum of 2009hz (cf. CBET
1897) were obtained at the Nordic Optical Telescope (+ ALFOSC; range 350-800
nm; resolution 1.8 nm) on Aug. 13.10 and 13.02 UT, respectively.  SN 2009hr
is an evolved type-Ia supernova.  Adopting a redshift z = 0.017, obtained
by measuring the position of the Si 635.5-nm absorption, 2009hr is found to
be most similar to the type-Ia supernova 1993H (spectrum from the ASA
archive) at about 40 days after maximum, according to GELATO (Harutyunyan
et al. 2008, A.Ap. 488, 383; https://gelato.tng.iac.es/login.cgi).  A
spectrum of 2009hz shows it to be a core-collapse supernova soon after
explosion; its very blue, featureless continuum recalls the spectra of very
young type-II or type-IIb supernovae.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2009 CBAT
2009 August 15                   (CBET 1907)              Daniel W. E. Green