Supernova 2014du in Ucg 1899 = Psn J02262331+2739348

F. Ciabattari, E. Mazzoni, and S. Donati, Borgo a Mozzano, Italy report their discovery of an apparent supernova (mag 17.4) on unfiltered CCD images (limiting mag 19.5) obtained on Oct. 31.84 and Nov. 1.96 UT with a 0.5-m Newtonian telescope (+ FLI 4710 Proline camera). The new object is located at R.A. = 2h26m23s.31, Decl. = +27d39'34".8 (equinox 2000.0; astrometry with respect to UCAC-2 stars), which is 38" west and 18" north of the center of the galaxy UGC 1899. Nothing is visible at this position on the digitized plates of the Palomar Sky Survey from 1991 Oct. 3 (F plate, limiting magnitude 20.3) and 1991 Sept. 14 (J plate, limiting magnitude 20.3). The variable was designated PSN J02262331+2739348 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2014du based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2014du: 2014 Oct. 20.054, [19.5 (S. Leonini, M. Conti, G. Guerrini, P. Rosi, and L. M. Tinjaca Ramirez, Siena, Italy; 0.53-m reflector; automatic survey of the Italian Supernovae Search Project); Oct. 26, 19.2 (Ciabattari et al.; near limit of detection); 30.942, 17.4 (Leonini et al.; pre-discovery image; position end figures 23s.23, 35".2); Nov. 2.739, 17.5 (G. Masi and P. Catalano; remotely using a 43-cm telescope near Ceccano, Italy; position end figures 23s.23, 34".9); 2.922, 17.5 (M. Caimmi, Loreto, Italy; 0.24-m f/6.5 reflector; thirteen stacked 30-s exposures; position end figures 23s.26, 34".5; reference stars from UCAC-4 catalogue; images posted at website URL http://www.oav.name/public/PSN_J02262331+2739348_20141102,9219.jpg). P. Ochner, L. Tomasella, S. Benetti, E. Cappellaro, N. Elias-Rosa, A. Pastorello, and M. Turatto, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that an optical spectrogram (range 340-820 nm; resolution 1.2 nm) of 2014du, obtained on Nov. 2.94 UT with the Asiago 182-cm Copernico Telescope (+ AFOSC) under the Asiago Transient Classification Program (Tomasella et al. 2014, AN 335, 841), shows that this is a type-Ia supernova. Adopting for the host galaxy (UCG 1899) a redshift of z = 0.0324 (Saintonge et al. 2008, A.J. 135, 588; via NED), a good match is found with several type-Ia supernovae around one week before B-band maximum light. An expansion velocity of about 14800 km/s is derived from the minimum of the Si II 635-nm line. 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.