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@eps.harvard.edu (alternate cbat@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