Electronic Telegram No. 2948 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 2011jc = PSN J03383439+2232595 A. J. Drake, S. G. Djorgovski, M. J. Graham, A. Mahabal, and R. Williams, California Institute of Technology; J. L. Prieto, Princeton University; M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the discovery of an apparent supernova in unfiltered Mount Lemmon Survey (MLS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011jc Nov. 30.26 3 38 34.39 +22 32 59.5 18.9 1".1 E, 16".7 N The variable was designated PSN J03383439+2232595 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011jc based on the spectroscopic confirmation reported below. Additional reported CCD magnitudes for 2011jc (unfiltered unless noted otherwise): Sept. 29.48 UT, [21.0 (MLS); Oct. 18.49, 19.6 (MLS); Dec. 4.336, 18.4 (L. Elenin, Lyubertsy, Russia; 0.45-m f/2.8 telescope + KAF09000 chip, remotely taken at the ISON-NM Observatory near Mayhill, NM, USA; position end figures 34s.39 +/- 0".1, 58".9 +/- 0".1; NOMAD reference stars; limiting mag about 19.8; image posted at website URL http://spaceobs.org/images/TOCP/PSNJ03383439+2232595-20111204.png); 10.961, R = 18.2 (Federica Luppi, Varese, Italy; 0.35-m f/7.9 reflector + Bessell R filter; position end figures 34s.37, 59".4; reference stars from CMC-14 catalogue); 19.900, 19.0 (S. Foglia and G. Galli, Pogliano Milanese, Italy; 0.28-m f/6.8 Schmidt-Cassegrain reflector + ST8-XME camera; position end figures 34s.38, 59".6; UCAC 2.0 reference stars). D. Wright and M. Fraser, Queen's University, Belfast; L. Tomasella, A. Pastorello, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and E. Kankare and S. Mattila, University of Turku; on behalf of a larger collaboration, report that low-S/N spectrograms of PSN J03383439+2232595 = SN 2011jc, obtained on Dec. 16.01 and 18.92 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 350-820 nm; resolution 2.4 nm), on Dec. 19.0 with the Nordic Optical Telescope (+ ALFOSC; range 320-910 nm; resolution 1.6 nm), and on Dec. 19.05 with the William Herschel Telescope (+ ISIS; range 300-975 nm; resolution 1.2 nm) show that 2011jc is a type-IIn supernova. The best fits to these spectra found by GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383; available at URL https://gelato.tng.iac.es/login.cgi) suggest that 2011jc is similar to SN 2005gj (comparison spectra are from Padova-Asiago Supernova Archive) a few days after explosion, if a redshift of 0.087 is assumed for the host galaxy. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 December 22 (CBET 2948) Daniel W. E. Green