2012CBET.3243....1C

Further to CBET 3199, S. B. Cenko, W. Li, and A. V. Filippenko report the LOSS discovery of an apparent supernova on unfiltered KAIT images:

---------------------------------------------------------------------------— SN 2012 UT R.A. (2000.0) Decl. Mag. Offset ---------------------------------------------------------------------------— 2012ff Aug. 21.38 23 05 48.71 +14 19 56.4 19.2 1".5 W, 3".3 N ---------------------------------------------------------------------------—

The variable was designated PSN J23054871+1419564 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012ff based on the spectroscopic confirmation reported below. Additional unfiltered CCD magnitudes for 2012ff: Aug. 15.41 UT, [19.5 (KAIT); Sept. 15.950, 18.1 (Xavier Bros, Ager, Spain; 35-cm f/6 reflector; position end figures 48s.88, 56".2; UCAC2 reference stars; image posted at the following website URL: http://anysllum.com/PSN_ANON_PEG_15092012.jpg).

J. M. Silverman, K. I. Clubb, P. Kelly, and A. V. Filippenko, University of California, Berkeley, report that inspection of a low-signal-to-noise-ratio CCD spectrogram (range 340-1000 nm), obtained on Sept. 7 UT with the Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory, shows that PSN J23054871+1419564 = SN 2012ff is a type-Ia supernova. Cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2012ff is a normal type-Ia supernova approximately 11 days past maximum brightness. After removal of the host-galaxy recession velocity of 32400 km/s, determined from narrow emission lines, the absorption minimum of the Si II 635.5-nm line is found to be blueshifted by 11400 km/s.