Electronic Telegram No. 2946 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 2011ja IN NGC 4945 = PSN J13051112-4931270 L. A. G. Monard, Calitzdorp, Western Cape, South Africa, reports his discovery of an apparent supernova (magnitude 14.0) on unfiltered CCD taken at the Klein Karoo Observatory on Dec. 18.086 UT. The new object is located at R.A. = 13h05m11s.09 +/- 0s.03, Decl. = -49d31'27".1 +/- 0".1 (equinox 2000.0; UCAC2 reference stars), which is 152" west and about 200" south of the core of the nearby SBcd-type galaxy NGC 4945 (note that the core of this late-type galaxy is not well-defined, which makes offset measurements difficult). Nothing is visible at this position in Digitized Sky Survey images (limiting red mag 20.5) or on earlier images taken by Monard (limiting mag 18.5 and deeper). The variable was designated PSN J13051112-4931270 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011ja based on the spectroscopic confirmation reported below. Additional CCD magnitudes reported for 2011ja: Nov. 28.091, [17.5 (Monard); Dec. 19.081, 13.9 (Monard); 20.751, 12.3 (Joseph Brimacombe, Cairns, Australia; 41-cm telescope + STL6K camera + infrared filter; range > 700 nm; position end figures 11s.13, 26".9; image posted at URL http://www.flickr.com/photos/43846774@N02/6546296733/). D. Milisavljevic, Harvard-Smithsonian Center for Astrophysics (CfA); R. Fesen, Dartmouth College; T. Pickering and E. Romero-Colmenero, South African Astronomical Observatory and Southern African Large Telescope; and Alicia Soderberg and Raffaella Margutti, CfA, report that low-dispersion spectra (range 350-880 nm), obtained on Dec. 19.1 UT during morning twilight with the 10-m SALT telescope (+ RSS), show PSN J13051112-4931270 = SN 2011ja to be a relatively young type-II supernova. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows a reasonable match to the type-IIP event SN 2004et about a week after maximum light. After removal of the host-galaxy recession velocity of 460 km/s (determined from narrow emission lines), the absorption minimum of the H-alpha line is found to be blueshifted by about -11000 km/s. A suppressed blue continuum and noticeable absorption around Na I are suggestive of significant internal extinction. M. Turatto, S. Benetti, A. Pastorello, S. Valenti, F. Bufano, and L. Tomasella, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, on behalf of a larger collaboration, report that a spectrogram of PSN J13051112-4931270 = SN 2011ja, obtained on Dec. 19.31 UT with the European Southern Observatory's New Technology Telescope (+ EFOSC2; range 365-930 nm; resolution 1.8 nm), shows it to be a type-II supernova. The best fit to this spectrum found by GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383; available at website URL https://gelato.tng.iac.es/login.cgi) suggests that 2011ja is similar to type-II supernovae a few days after explosion, if a redshift of 0.001878 for the host galaxy (Koribalski et al. 2004, A.J. 128, 16; via NED) and a total reddening of E(B-V) > 1.2 are assumed. Together with H lines with broad P-Cyg profiles, absorptions of Fe II, Ca II, and He I are clearly detected. S. Ryder, Australian Astronomical Observatory; A. Soderberg, Harvard University; C. Stockdale, Marquette University; S. Van Dyk, Spitzer Science Center, California Institute of Technology; S. Immler, Goddard Space Flight Center; K. Weiler, Naval Research Laboratory; and N. Panagia, Space Telescope Science Institute and Observatory of Catania, report the detection of radio emission near the position of SN 2011ja with the Australia Telescope Compact Array radio telescope, confirming its core-collapse nature. A flux density of 0.44 +/- 0.20 mJy was measured at 18.0 GHz on Dec 19.9 UT. The measured position of the radio emission of R.A. = 13h05m11s.06, Decl. = -49o31'26".0 (equinox 2000.0) is in good agreement with the measured optical position (end figures 11s.12, 27".0). Radio observations of this nearby (4 Mpc, from NED) supernova at the Australia Telescope Compact Array are continuing. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 December 21 (CBET 2946) Daniel W. E. Green