Electronic Telegram No. 4183 Central Bureau for Astronomical Telegrams Mailing address: 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 2015aj IN UGC 3460 = PSN J06280368+7418338 Paolo Campaner reports the discovery of an apparent supernova (mag 18.3) on three 75-s unfiltered CCD exposures (limiting magnitude 20.0) obtained on Sept. 2.100 UT with a 0.4-m f/5.5 reflector at Ponte di Piave, Italy, in the course of the Italian Supernovae Search Project. The new object is located at R.A. = 6h28m03s.68, Decl. = +74d18'33".8 (equinox 2000.0), which is 18" east and 28" north of the center of UGC 3460. The variable was designated PSN J06280368+7418338 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2015aj based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2015aj: Sept. 3.01, 18.2 (M. Caimmi, Loreto, Italy; 0.24-m f/6.5 reflector; fifteen stacked 240-s exposures; position end figures 03s.74, 34".1); 4.124, 18.1 (Campaner); 7.382, 17.6 (J. Brimacombe, Cairns, Australia; position end figures 03s.61, 34".2; image posted at URL https://www.flickr.com/photos/43846774@N02/21082868068/); 12.904, 17.0 (G. Masi; remotely using a 43-cm telescope at Ceccano, Italy; position end figures 03s.57, 34".0); 18.902, 17.7 (Zhijian Xu and Xing Gao; Celestron C14 telescope; position end figures 03s.56, 34".3; image posted at URL http://njzhijian.lamost.org/Supernova/PSN_J06280368+7418338_0918.jpg). P. Ochner, A. Pastorello, S. Benetti, E. Cappellaro, N. Elias-Rosa, L. Tartaglia, G. Terreran, L. Tomasella, and M. Turatto, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that an optical spectrogram (range 340-820 nm; resolution 1.4 nm) of PSN J06280368+7418338 = SN 2015aj, obtained on Aug. 6.09 UT with the Asiago 182-cm Copernico Telescope (+ AFOSC) in the framework of the Asiago Transient Classification Program (Tomasella et al. 2014, A.N. 335, 841), shows that this a type-II supernova, few weeks after maximum light. The spectrum shows P-Cyg lines of H, Fe II, and Na I that are typically observed in type-II supernovae during the H-recombination phase. From the minimum of H-alpha, they infer an ejecta velocity of about 6200 km/s (slightly lower, about 5100 km/s, from the minimum of H-beta), when adopting for the host galaxy (UGC 3460) a redshift z = 0.01765 (de Vaucouleurs et al. 1991, RC3.9; via NED). The classification was done with GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024). The Asiago classification spectra are posted at URL http://sngroup.oapd.inaf.it. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2015 CBAT 2015 November 17 (CBET 4183) Daniel W. E. Green