Electronic Telegram No. 901 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html SUPERNOVA 2007av IN NGC 3279 R. Arbour, South Wonston, Hants, U.K., reports his discovery of an apparent supernova (mag 15.5) on several unfiltered CCD images (limiting mag 18.0) taken on Mar. 20.8352 UT using a 0.3-m f/6.3 Schmidt-Cassegrain reflector (+ Starlight Xpress CCD camera) in the course of his supernova patrol. The new object is located at R.A. = 10h34m43s.17, Decl. = +11o11'38".3 (equinox 2000.0), which is 5".9 east and 14".9 south of the center of the galaxy NGC 3279 = IC 622. Nothing is visible at this position on the Digitized Sky Survey plates from 1996 Mar. 18 (blue) and 1993 Mar. 22 (red). Arbour adds that, at his request, D. Briggs obtained a confirming image on Mar. 20.873 with a 0.40-m f/4.5 reflector, measuring position end figures 43s.17, 37".9 for 2007av, estimating its brightness as mag 15.2. Arbour also obtained confirming unfiltered CCD images (limiting mag 19.0) around Mar. 21.831 with a 0.40-m f/5 reflector, showing 2007av at the same position and approximately the same brightness. Following posting of this object on the Central Bureau's unconfirmed-objects webpage, G. Folatelli and N. Morrell, on behalf of the Carnegie Supernova Project, report the confirmation of 2007av in a combination of eighteen Y-band images obtained between Mar. 21.24 and 21.27 UT with the 1-m Swope telescope (+ RetroCam) at Las Campanas Observatory, providing the following measured position for 2007av: R.A. = 10h34m43s.13, Decl. = +11o11'37".1 (equinox 2000.0). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 March 21 (CBET 901) Daniel W. E. Green