Electronic Telegram No. 5490 Central Bureau for Astronomical Telegrams Mailing address: Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network (2680) MATEO R. Durkee, Shed of Science South Observatory, Pontotoc, TX, U.S.A.; P. Pravec, Ondrejov Observatory; V. Benishek, Belgrade Astronomical Observatory; A. Marchini and R. Papini, Dipartimento di Scienze Fisiche, Della Terra e Dell'Ambiente, University of Siena; D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.; and J. Oey, Blue Mountains Observatory, Leura, NSW, Australia, report that photometric observations taken with a 0.50-m telescope at the Shed of Science South Observatory, a 0.35-m telescope at the Sopot Observatory in Serbia, a 0.30-m telescope at the Astronomical Observatory of the University of Siena, a 0.63-m telescope at the Sugarloaf Mountain Observatory, and a 0.35-m telescope at the Blue Mountains Observatory during 2024 Oct. 22-Nov. 24 reveal that minor planet (2680) is a binary system with an orbital period of 53.20 +/- 0.02 hr. The primary shows a period of 3.31306 +/- 0.00008 hr and has a lightcurve amplitude of 0.11 magnitude at solar phases 2-10 degrees, suggesting a nearly spheroidal shape. Mutual eclipse/occultation events that are 0.14 magnitude deep indicate a lower limit on the secondary-to-primary mean-diameter ratio of 0.37. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2025 CBAT 2025 January 8 (CBET 5490) Daniel W. E. Green