Electronic Telegram No. 2173 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Room 209; Dept. of Earth and Planetary Sciences; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbat@cfa.harvard.edu; dwe_green@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2010Z IN NGC 2797 I. K. W. Kleiser, J. M. Silverman, A. J. L. Morton, and A. V. Filippenko, University of California, Berkeley, report that inspection of a CCD spectrum (range 340-1020 nm), obtained on Feb. 14 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that 2010Z (CBET 2169) is a type-II supernova. After removal of the host-galaxy recession velocity of 7600 km/s, determined from narrow emission lines, the absorption minimum of the H-alpha line is found to be blueshifted by 8700 km/s and is much weaker than the emission component. Cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2010Z is within a week or two of maximum light. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 February 14 (CBET 2173) Daniel W. E. Green