Electronic Telegram No. 535 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 2004 DC P. A. Taylor and J. L. Margot, Cornell University; M. C. Nolan, National Astronomy and Ionosphere Center; L. A. M. Benner, S. J. Ostro, and J. D. Giorgini, Jet Propulsion Laboratory; and C. Magri, University of Maine at Farmington, write that Arecibo (2380-MHz, 12.6-cm) radar observations on June 2 UT show that the Apollo-type minor planet 2004 DC (cf. MPECs 2004-D05, 2006-L08) is a binary system. Preliminary estimates of the diameters, based on visible range extents, are 300 m for the primary and 60 m for the secondary. The range-Doppler separation between components was 300 m at 0.7 Hz on June 2.46. Photometric observations are encouraged. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 June 2 (CBET 535) Daniel W. E. Green