Electronic Telegram No. 2668 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 2011an IN UGC 4139 = PSN J07592442+1625082 S. Howerton, Arkansas City, KS, U.S.A.; A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; J. L. Prieto, Carnegie Observatories; 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 Catalina Real-time Transient Survey's discovery of an apparent supernova in public images from the Catalina Sky Survey. SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011an Mar. 1.19 7 59 24.42 +16 25 08.2 18.4 11".6 E, 8".5 S This object was designated PSN J07592442+1625082 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011an based on the spectroscopy reported below. Further unfiltered CCD magnitudes for 2011an: Jan. 28.26 UT, [20.5 (Mt. Lemmon Survey); Mar. 2.13, 16.9 (Howerton, 0.2-m telescope); Mar. 3.269, 15.7 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera at New Mexico Skies Observatory, Mayhill, NM, U.S.A.; position end figures 24s.38, 09".1). Brimacombe has posted his image at URL http://www.flickr.com/photos/43846774@N02/5493974475/. The presumed host galaxy is UGC 4139 = PGC 22391. 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 J07592442+1625082 = 2011an was obtained on Mar. 5 UT by M. Calkins 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 2011an is a type-IIn supernova, similar to SN 2001fa near maximum light. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 March 7 (CBET 2668) Daniel W. E. Green