Electronic Telegram No. 440 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 2006at S. Blondin, M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics, and T. Matheson, National Optical Astronomy Observatory, report that a spectrum (range 350-740 nm) of SN 2006at (cf. IAUC 8687), obtained on Mar. 23.38 UT by W. Peters with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), shows this object to be a type-II supernova. The spectrum consists of a blue continuum and P-Cyg profiles of the Balmer series and other lines (see http://cfa-www.harvard.edu/oir/Research/supernova/spectra/sn2006at-20060323.flm. No nebular lines from the supernova's host galaxy were detected in the supernova spectrum. However, cross correlation with a library of type-II-supernova spectra indicates that SN 2006at is at an approximate redshift of z = 0.015 (cz = 4500 km/s). Adopting this value for the recession velocity of the supernova, the maximum absorption in the H_beta line (rest 486.1 nm) is blueshifted by 7000 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 March 24 (CBET 440) Daniel W. E. Green