Electronic Telegram No. 2074 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://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2009mh IN NGC 3839 S. Nakano, Sumoto, Japan, reports the discovery by Koichi Itagaki (Teppo-cho, Yamagata, Japan) of an apparent supernova (mag 16.6) on unfiltered CCD frames (limiting mag 19.0) taken on Dec. 12.779 UT using a 0.30-m f/7.8 reflector at the Takanezawa Station, Tochigi-ken. The new object is located at R.A. = 11h43m55s.93, Decl. = +10o46'55".2 (equinox 2000.0), which is 23" east and 10" south of the center of NGC 3839. Nothing is visible at this position on the Digitized Sky Survey or on his image of NGC 3839 taken on 2002 Jan. 19 (limiting mag 19.0). Itagaki has posted the discovery image at website URL http://www.k-itagaki.jp/images/psn3839.jpg. Nakano adds that six co-added 120-s confirming unfiltered CCD images (limiting mag 18.6), obtained by T. Yusa (Osaki, Miyagi-ken, Japan; remotely using a 0.25-m f/3.4 reflector near Mayhill, NM, U.S.A.) on Dec. 13.39, yield mag 16.7 and position end figures 55s.93, 55".2. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 December 13 (CBET 2074) Daniel W. E. Green