[IAUC] CBET 1273: 20080229 : SUPERNOVA 2008ar IN IC 3284

[IAUC mailing list]

                                                  Electronic Telegram No. 1273
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS en CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT en CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVA 2008ar IN IC 3284
     F. Yuan, University of Michigan; R. Quimby, California Institute of
Technology; D. Chamarro, M. D. Sisson, and C. Akerlof, University of Michigan;
and J. C. Wheeler, University of Texas, on behalf of the ROTSE collaboration,
report the discovery of a supernova in unfiltered CCD images taken with the
0.45-m ROTSE-IIIb telescope at McDonald Observatory.  The supernova is located
at R.A. = 12h24m37s.92, Decl. = +10o50'17".4 (equinox 2000.0), which is 5".3
east and 3".1 south of the center of IC 3284; 2008ar was discovered on Feb.
27.25 UT at mag about 16.9 and imaged again on Feb. 28.25 at mag about 16.0.
     A spectrogram (range 420-890 nm) of 2008ar, obtained on Feb. 28.29 with
the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by
S. Rostopchin and A. Westfall, shows it to be a type-Ia supernova.  The data
are similar to the pre-maximum spectra of normal type-Ia supernovae, such as
SN 1992A (Kirshner et al. 1993, Ap.J. 415, 589), but with features
significantly extended to the blue.  Correcting for the SDSS redshift of the
host (z = 0.026), the minimum of the Si II 635.5-nm feature is blueshifted by
14300 km/s.  The Ca II infrared absorption is unusually strong, and the line
minimum is blueshifted by 23600 km/s.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 February 29                 (CBET 1273)              Daniel W. E. Green