Electronic Telegram No. 270 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 (9260) EDWARDOLSON M. Jakubik and M. Husarik, Skalnate Pleso Observatory; J. Vilagi, S. Gajdos, and A. Galad, Modra Observatory; P. Pravec and P. Kusnirak, Ondrejov Observatory; W. Cooney, J. Gross and D. Terrell via Sonoita Research Observatory (Sonoita, AZ); D. Pray, Greene, RI; and R. Stephens, Yucca Valley, CA, report that photometric observations obtained during Oct. 6-30 show that the minor planet (9260) is a binary system with an orbital period of 17.785 +/- 0.003 hr. The primary rotates with a period of 3.0852 +/- 0.0001 hr, and its lightcurve amplitude of 0.11 mag is indicative of a nearly spheroidal shape. Mutual eclipse/occultation events that are 0.08-0.15 mag deep indicate a secondary-to-primary mean-diameter ratio of 0.27 +/- 0.03. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2005 CBAT 2005 November 2 (CBET 270) Daniel W. E. Green