Electronic Telegram No. 1278 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 SUPERNOVAE 2008au AND 2008av A. J. Drake, A. Mahabal, S. G. Djorgovski, M. J. Graham, and R. Williams, California Institute of Technology; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the discovery of two apparent supernovae that have been detected in sequences of four 30-s exposures via the Catalina Sky Survey (CSS) with the 0.7-m f/1.9 Catalina Schmidt telescope (+ 4000x4000 camera): SN 2008 UT R.A. (2000.0) Decl. Mag. Offset 2008au Feb. 27.33 11 30 33.95 +13 09 05.3 18.7 11".4 W, 9".0 S 2008av Mar. 2.50 14 57 26.27 +23 23 48.3 19.1 3" W, 17" S SN 2008au is near the edge of a galaxy catalogued by the Sloan Digital Sky Survey (SDSS) with z = 0.082 and magnitudes g about 17.9 and r about 17.6. The new object is not seen in CSS images reaching mag approximately 20 taken on (and before) Jan. 31.36 UT, nor is 2008au present in prior CSS co-added images (reaching V mag approximately 21.5) or in Digitized Sky Survey (DSS), SDSS, and Palomar-Quest images (reaching mag around 23). R. Robb and D. Balam, Department of Physics and Astronomy, University of Victoria, confirm the presence of 2008au as a star of magnitude g(SDSS) = 18.65 on Mar. 1.32 on CCD images obtained with the 1.82-m Plaskett Telescope of the National Research Council of Canada; their comparison with the Palomar Observatory Sky Survey shows nothing at the position of 2008au (measured position end figures 33s.95, 05".3; the tabulated offset above is from Robb and Balam). Specific details and links to discovery data for 2008au can be found at the following URL: http://voeventnet.caltech.edu/feeds/ATEL/CSS/802271120614120311.html SN 2008av, which appears to be associated with the galaxy 2MASX J14572647+2324051 (g about 17.2, r about 16.5), was confirmed via prediscovery CSS images taken on Feb. 8.44 and 18.47, when the new object was at mag 18.0 and 18.8, respectively. Nothing is present at this position in CSS images reaching mag about 20 on Jan. 1.54 UT, nor is 2008av present in prior CSS co-added images or in Digitized Sky Survey (DSS), SDSS, and Palomar-Quest images (reaching mag around 23). Specific details and links to discovery data for 2008av can be found at the following website URL: http://voeventnet.caltech.edu/feeds/ATEL/CSS/803021230744111099.atel.html NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 March 3 (CBET 1278) Daniel W. E. Green