Supernova 2011gg = Psn J00462108-0909277

Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gg Sep. 20.32 00 46 21.08 - 9 09 27.7 17.6 4".5 W, 1".1 S This variable was designated PSN J00462108-0909277 when it was posted on the Central Bureau's TOCP webpage and is here designated SN 2011gg based on the spectroscopic report below. Further unfiltered CCD magnitudes for 2011gg: Sept. 24.34 UT, 17.4 (CSS); 27.407, 16.9 (Joseph Brimacombe, Cairns, Australia; position end figures 21s.05, 28".6; image posted at the following website URL: http://www.flickr.com/photos/43846774@N02/6191346245/). S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 360-810 nm; resolution 2.2 nm) of PSN J00462108-0909277 = SN 2011gg, obtained on Sept. 26.01 UT, suggests that it 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) suggests a normal type-Ia supernova about one week before the B-band maximum at a redshift z = 0.055. The expansion velocity derived from the Si II 635.5-nm minimum is then about 10500 km/s....