Electronic Telegram No. 2682 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 2011ba = PSN J08230906+1604170 K. Sarneczky, Konkoly Observatory; and Z. Kuli, Hungarian Astronomical Association, report their discovery of a possible supernova (mag 19.6) in 30-min co-added unfiltered CCD images (limiting mag 21.5) taken on Mar. 24.81 UT with the 0.60-m Schmidt telescope at Konkoly Observatory at Piszkesteto, Hungary. The new object is located at R.A. = 8h23m09s.06, Decl. = +16d04'17".0 (equinox 2000.0). Nothing is visible at this position on a Sloan Digital Sky Survey image (no information given regarding bandpass, date, or limiting magnitude). This object was designated PSN J08230906+1604170 when posted on the Central Bureau's TOCP webpage and is designated SN 2011ba here based on the spectroscopy reported below. Additional unfiltered magnitudes for PSN J08230906+1604170 with the Schmidt telescope: Jan. 3.96 UT, [20.5; Mar. 8.85, [21.8 (J. Kelemen and Sarneczky); 25.81, 19.6; 28.77, R = 19.5, B = 20.1 (Sarneczky and Kuli); 30.81, R = 19.6 (Sarneczky and Kuli). Additional unfiltered CCD magnitudes by Joseph Brimacombe (Cairns, Australia) for 2011ba from images obtained remotely: Mar. 27.456 UT, 19.9 (40.6-cm RCOS telescope + U9000 camera at Macedon Ranges Observatory, near Melbourne, Australia; position end figures 09s.13, 16".2); 28.151, 19.8 (51-cm RCOS telescope + STL11K camera at New Mexico Skies Observatory, Mayhill, NM, U.S.A.; position end figures 09s.09, 16".3). Brimacombe's image from Mar. 28 is posted at http://www.flickr.com/photos/43846774@N02/5578391946/. J. Vinko, University of Szeged; G. H. Marion, Harvard-Smithsonian Center for Astrophysics and University of Texas; and J. C. Wheeler, University of Texas, report that a spectrum of PSN J08230906+1604170 = SN 2011ba, obtained on Apr. 1.2 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by J. Caldwell, shows it to be a type-Ia supernova. The spectrum shows the prominent Si II 635.5-nm feature and several other spectral features that are characteristic of a normal type-Ia supernova at or a few days after maximum light. According to SNID tool (Blondin and Tonry 2007, Ap.J. 666, 1024), the spectrum closely resembles that of SN 2001ay at three days after maximum. The median redshift estimated from the supernova features is z = 0.144. Adopting this redshift, the photospheric velocity from the blueshift of the Si II 635.5-nm feature is about 12400 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 April 6 (CBET 2682) Daniel W. E. Green