Supernova 2011hb = PSN J23275551+0846457

Report the discovery of an apparent supernova in public images from the Catalina Sky Survey (CSS). SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011hb Oct. 24.24 23 27 55.51 + 8 46 45.7 18.8 6".7 W, 25".2 S The variable was designated PSN J23275551+0846457 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011hb based on the spectroscopic confirmation reported below. Additional unfiltered CCD magnitudes for 2011hb: Oct. 6.19 UT, [20.5 (CSS); 16.24, 20.3 (CSS); 26.082, 17.3 (L. Elenin, remotely using a 0.45-m f/2.8 astrograph at the ISON-NM Observatory near Mayhill, NM, USA; limiting mag about 19.7; position end figures 55.s.55, 45".5; NOMAD reference stars; image posted at website URL http://spaceobs.org/images/TOCP/PSNJ23275551+0846457.jpg); 26.142, 17.5 (C. Jacques and E. Pimentel, Belo Horizonte, Brazil; remotely using the GRAS G05 telescope in New Mexico; position end figures 55s.59, 45".2; UCAC2 reference stars; limiting magnitude 19.0; image posted at the following website URL: http://ceamig-rea.net/tocp/ngc7674_tocp.jpg). G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm) of PSN J23275551+0846457 = SN 2011hb was obtained on Oct. 28 UT by P. Berlind with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011hb is a type-Ia supernova several days before maximum light. SNID finds that the best fit is to a template from the normal type-Ia supernova 2005cf at -10 days. The Si II 635.5-nm feature is broad and asymmetrical; an estimated redshift of z = 0.028924 for NGC 7674 (Nishiura et al. 2000, A.J. 120, 1691) is used to measure the velocity at the minimum of this feature to be about 14700 km/s