Electronic Telegram No. 3094 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 2012bx = PSN 11442941+0703463 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 Catalina Sky Survey (CSS) images: SN 2012 UT R.A. (2000.0) Decl. Mag. Offset 2012bx Apr. 11.24 11 44 29.41 + 7 03 46.3 17.1 16".5 W, 8".8 N The variable was designated PSN J11442941+0703463 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012bx based on the spectroscopic confirmation reported below. Further CCD magnitudes for 2012bx (unfiltered unless noted otherwise): Mar. 17.31 UT, [21.5 (CSS); Apr. 14.040, 17.2 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera + luminance filter at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 29s.42, 46".4; image posted at URL http://www.flickr.com/photos/43846774@N02/6936349786/); 15.838, 16.8 (Nick James, Chelmsford, Essex, England; Celestron 11 telescope + ST9XE camera; position end figures 29s.39, 46".5); 16.343, 17.2 (Brimacombe; position end figures 29s.41, 46".1); 18.26, 17.3 (CSS); 21.023, 17.6 (F. Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8 reflector; position end figures 29s.42, 46".7; reference stars from CMC-14 catalogue; image posted at URL http://www.astrogeo.va.it/pub/TOCP/PSN_J11442941+0703463.jpg). Brimacombe's Apr. 16 image is posted at the following website URL: http://www.flickr.com/photos/43846774@N02/7085286249/. L. Tomasella, S. Benetti, E. Cappellaro, P. Ochner, A. Pastorello, M. Turatto, and S. Valenti, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that a spectrogram of PSN 11442941+0703463 = 2012bx, obtained on Apr. 24.99 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 2.4 nm), indicates that this is a type-Ia supernova. Cross-correlation with a library of supernova spectra via the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2012bx is similar to SN 1995D (Sadakane et al. 1996, PASJ 48, 51) at 11 days after maximum at a redshift z = 0.049. The redshift is fully consistent with the redshift of the host galaxy, SDSS J114430.51+070337.6 (z = 0.0508, Sloan Digital Sky Survey Data Release 5, as obtained from website URL http://www.sdss.org/dr5/products/catalogs/index.html). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 April 26 (CBET 3094) Daniel W. E. Green