V. Benishek, Belgrade Astronomical Observatory; P. Pravec, Ondrejov Observatory; A. Aznar, Isaac Aznar Observatory, Centro Astronomico del Alto Turia, Aras de los Olmos, Spain; A. Marchini, R. Papini, and F. Salvaggio, Dipartimento di Scienze Fisiche, Della Terra e Dell’Ambiente, University of Siena; D. Pray, Sugarloaf Mountain observatory, South Deerfield, MA, U.S.A.; and R. Montaigut and A. Leroy, OPERA Observatory, France, report that photometric observations taken with a 0.35-m telescope at the Sopot Observatory in Serbia, a 0.35-m telescope at the Isaac Aznar Observatory, a 0.30-m telescope at the Astronomical Observatory of the University of Siena, a 0.50-m telescope at the Sugarloaf Mountain Observatory, and a 0.20-m telescope at the OPERA Observatory during 2016 Sept. 13-29 reveal that minor planet (5536) is a binary system with an orbital period of 16.325 +/- 0.005 hr. The primary shows a period of 3.5830 +/- 0.0002 hr and has a lightcurve amplitude of 0.09 mag at solar phases 11-18 degrees, suggesting a nearly spheroidal shape. Mutual eclipse/occultation events that are 0.10- to 0.19-magnitude deep indicate a secondary-to-primary mean-diameter ratio of 0.31 +/- 0.02. NOTE: These ‘Central Bureau Electronic Telegrams’ are sometimes superseded by text appearing later in the printed IAU Circulars.
2016 October 9 (CBET 4336) Daniel W. E. Green