Electronic Telegram No. 5331 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 (82256) 2001 KM_8 V. Benishek, Belgrade Astronomical Observatory; and P. Pravec, Ondrejov Observatory, report that photometric observations taken with a 0.35-m telescope at the Sopot Observatory in Serbia during 2023 Nov. 7-2024 Jan. 4 reveal that minor planet (82256) is a binary system with an orbital period of 43.17 +/- 0.06 hr. The primary shows a period of 3.0362 +/- 0.0003 hr and has a lightcurve amplitude of 0.37 mag at solar phases 4-11 degrees. Mutual eclipse/occultation events that are 0.08 magnitude deep indicate a lower limit on the secondary-to-primary mean-diameter ratio of 0.28. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2024 CBAT 2024 January 15 (CBET 5331) Daniel W. E. Green