Electronic Telegram No. 1530
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 2008ga AND 2008gb
     T. N. Steele, C. V. Griffith, R. Chornock, and A. V. Filippenko,
University of California, Berkeley, report that inspection of CCD spectra
(range 330-1010 nm), obtained on Oct. 7 UT with the 3-m Shane reflector
(+ Kast) at Lick Observatory, shows that 2008ga (CBET 1526) is a type-II
supernova; H-alpha has a well-developed P-Cyg profile.  After removal of
the host-galaxy recession velocity of 4600 km/s (Ragaigne et al. 2003,
A.Ap. 408, 67), the FWHM of the H-alpha emission component is measured to
be 2900 km/s.  SN 2008gb (CBET 1527) is a normal type-Ia supernova, near
maximum brightness.
     P. Garnavich, K. Mohrig, and N. Mancinelli, University of Notre Dame;
and B. Dilday, Rutgers University, report that spectra (range 350-900 nm;
resolution 0.67 nm) of 2008gb were obtained with the 3.5-m Apache Point
Observatory telescope (+ Dual Imaging Spectrograph) on Oct. 7.5 UT.  The
spectra show the supernova to be of type Ia, a few days before maximum
light.  H_alpha emission from the host galaxy indicates a redshift of
0.037.  The deep Si II absorption minimum shows a blue shift of 11400 km/s.
The ratio of the 580-nm/615-nm line depths suggests a mildly-fast-declining
light curve with a delta_m15(B) parameter (Garnavich et al. 2004, Ap.J.
613, 1120) of 1.3.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 October 7                   (CBET 1530)              Daniel W. E. Green