[IAUC] CBET 3231: 20120917 : SUPERNOVA 2012eu = PSN J03130416-0823317

Dom Sep 16 18:59:36 ART 2012

                                                  Electronic Telegram No. 3231
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 en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2012eu = PSN J03130416-0823317
     M. T-C. Yang, S. G. Djorgovski, A. J. Drake, M. J. Graham, and A. Mahabal
California Institute of Technology; J. L. Prieto, Princeton University; M.
Catelan, Pontificia Universidad Catolica de Chile; R. H. McNaught, Australian
National University; E. Christensen and S. M. Larson, Lunar and Planetary
Laboratory, University of Arizona, report the discovery of a supernova in
unfiltered Siding Spring Survey (SSS) images:

 SN       2012 UT       R.A. (2000.0) Decl.      Mag.      Offset
 2012eu   Aug. 27.77   3 13 04.16  - 8 23 31.7   17.3    0".6 W, 23".1 N

A spectrogram (with range 380-720 nm) was taken with the Palomar 5-m reflector
(+ DSBS) on Sept. 9.44 UT. Cross-correlation with a library of supernova
spectra using the "Supernova Identification" code (SNID; Blondin and Tonry
2007, Ap.J. 666, 1024) shows that 2012eu is a type-Ia supernova approximately
four weeks past maximum light at redshift z = 0.03.
     The variable was designated PSN J03130416-0823317 when it was posted at
the Central Bureau's TOCP webpage and is here designated SN 2012eu based on
the spectroscopic confirmation reported above and below.  Further CCD
magnitudes for 2012eu:  2011 Dec. 31.24, [19.5 (Catalina Sky Survey); 2012
Aug. 30.813, 18.1 (Joseph Brimacombe, Cairns, Australia; infrared filter,
bandpass > 700 nm; position end figures 04s.12, 31".5; image posted at
website URL http://www.flickr.com/photos/43846774@N02/7900306040/); Sept.
4.80, 18.0 (SSS); 7.128, 18.0 (Federica Luppi and Luca Buzzi, Varese, Italy;
0.38-m f/6.8 reflector; position end figures 04s.16, 31".2; reference stars
from CMC-14 catalogue; image posted at the following website URL:
URL:http://www.astrogeo.va.it/pub/TOCP/PSN_J03130416-0823317.jpg).

     L. Morelli and A. Pizzella, University of Padova; M. Dennefeld, Institute
d'Astrophysique de Paris and University of Paris 6; L. Tomasella and S.
Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di
Padova; and the NEON school (cf. IAUC 7664) students A. Khan Ali (Spain), H.
Finley (France), T. Kopytova (Germany), and L. Puspitarini (France), report
that a spectrogram of PSN J03130416-0823317 = 2012eu, obtained on Sept. 15.06
UT with the 1.82-m Copernico telescope (+ Afosc spectrograph; range 350-820
nm, resolution 1.3 nm), shows it to be type-Ia supernova.  Adopting for the
host galaxy (PGC 145362) a redshift z = 0.029981 (SDSS Vol.1 2003; via NED),
comparison with a library of supernova spectra via GELATO (Harutyuyan et al.
2008, A.Ap. 488, 383) shows that 2012eu is a type-Ia event similar to several
type-Ia supernovae at one month after maximum light.  The expansion velocity
measured from the Si II 635.5-nm minimum is about 9000 km/s.


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

                         (C) Copyright 2012 CBAT
2012 September 17                (CBET 3231)              Daniel W. E. Green