Electronic Telegram No. 2662 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 2011ai = PSN J14290502+4154427 E. Briggs, J. Newton, and T. Puckett report the discovery of an apparent supernova (mag 17.0) on unfiltered CCD images (limiting mag 19.0) taken with a 0.40-m reflector at Portal, AZ, U.S.A., on Feb. 24.442 UT, in the course of the Puckett Observatory Supernova Search. The new object (which was designated PSN J14290502+4154427 when posted at the Central Bureau's TOCP webpage and is given the permanent designation SN 2011ai here) is located at R.A. = 14h29m05s.02, Decl. = +41o54m42s.7 (equinox 2000.0), which is 6".8 west and 11".8 north of the center of PGC 2188954. Additional unfiltered CCD magnitudes for 2011ai: Jan. 9, [19.3 (Puckett); Feb. 25.375, 16.9 (Puckett); 27.301, 16.6 (R. A. Koff, Bennett, CO, U.S.A.; position end figures 05s.05, 41".9 (UCAC3 catalogue). G. H. Marion and P. Challis, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm) of 2011ai was obtained on Mar. 1 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 2011ai is a type-Ia supernova near maximum light. The velocity of the Si II 635.5-nm feature, measured at the absorption minimum, is 11600 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 March 1 (CBET 2662) Daniel W. E. Green