Electronic Telegram No. 3128

Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2012cn IN MCG +11-15-28 = PSN J12082446+6256340
     T. Boles, Coddenham, England, reports the discovery of an apparent
supernova (mag 18.2) on unfiltered CCD images taken on May 14.989 and 15.983
UT with a 0.35-m reflector.  The new object is located at R.A. = 12h08m24s.46,
Decl. = +62o56'24".0 (equinox 2000.0), which is approximately 0".2 east and
6".3 south of the center of MCG +11-15-28 = PGC 38541.  The variable was
designated PSN J12082446+6256340 when it was posted at the Central Bureau's
TOCP webpage (where, due to a posting error in the position on the TOCP, the
declination was off by 10") and is here designated SN 2012cn based on the
spectroscopic confirmation reported below.  Additional magnitudes for 2012cn:
1995 Apr. 25, [21.0 (Digitized Sky Survey, blue plate; via Boles); 1996 Dec.
19, [20.5 (Digitized Sky Survey, red plate; via Boles); 2011 Feb. 12, [19.5
(Boles); Apr. 10, [19.5 (Boles); 2012 May 17.333, 17.8 (Joseph Brimacombe,
Cairns, Australia; luminance filter; position end figures 24s.52, 23".8;
image posted at URL http://www.flickr.com/photos/43846774@N02/7218910198/);
18.848, R_c = 17.1 (Massimiliano Martignoni, Magnago, Italy; 0.25-m f/10
reflector; position end figures 24s.50, 25".0).

     M. Fraser, R. Kotak, S. J. Smartt, Queen's University, Belfast, report
that a spectrum (range 330-975 nm; resolution about 1000) of PSN
J12082446+6256340 = 2012cn was obtained on May 25.89 UT with the 4.2-m William
Herschel Telescope (+ ISIS).  The spectrum was cross-correlated with a library
of supernova spectra via the "Supernova Identification" code (SNID; Blondin
and Tonry 2007, Ap.J. 666, 1024), and a good match was found to several normal
type-Ia supernovae at a redshift of z = 0.04, either at maximum light or a few
days before.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 May 29                      (CBET 3128)              Daniel W. E. Green