Electronic Telegram No. 2936 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 2011is IN NGC 5409 = PSN J14014716+0929488 [Editor's note: this text replaces that on CBET 2935 (last digit of designation corrected).] Alessandro Dimai, Cortina d'Ampezzo, Italy, on behalf of the Italian Supernovae Search Project (ISSP), reports the discovery by Merco Migliardi of an apparent supernova on unfiltered CCD images (limiting mag about 18.0) taken with the "Maioni" 0.28-m telescope of the Col Drusci Observatory on Nov. 21.178 (when the new object was at mag about 17.0) and 22.209 UT (at mag about 16.5). The variable is located at R.A. = 14h01m47s.00, Decl. = +09d29'50".1 (equinox 2000.0), which is 16" east and 24" north of the nucleus of NGC 5409. Nothing is visible at this position on Palomar Sky Survey infrared, red, and blue plates. The variable was designated PSN J14014716+0929488 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011is based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2011is (unfiltered unless noted otherwise): Apr. 9, [19.5 (ISSP, via Dimai); Nov. 23.515, 17.4 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera + luminance filter at the New Mexico Skies Observatory near Mayhill, New Mexico; position end figures 46s.99, 50".9; his image is posted at the following website URL: http://www.flickr.com/photos/43846774@N02/6391358701/); 25.211, 17.0 (Federica Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8 reflector; position end figures 46s.92, 50".8; reference stars from the NOMAD catalogue; image posted at website URL http://www.astrogeo.va.it/pub/TOCP/PSN_N5409.jpg); 27.20, 16.6 (Dimai). L. Tomasella, A. Pastorello, S. Valenti, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, on behalf of a larger collaboration, report that a spectrogram of PSN J14014716+0929488 = SN 2011is, obtained on Nov. 28.23 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 350-820 nm, resolution 2.4 nm), shows iT to be a type-Ia supernova. The best fit to this spectrum found by GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383; available at URL https://gelato.tng.iac.es/login.cgi) suggests that 2011is is a type-Ia supernova about 50 days after maximum light, adopting for the host galaxy a redshift of z = 0.02088 (Beers et al. 1995, A.J. 109, 874; via NED). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 December 5 (CBET 2936) Daniel W. E. Green