Electronic Telegram No. 5731
Central Bureau for Astronomical Telegrams
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(25251) 1998 UL_25
      V. Benishek, Belgrade Astronomical Observatory; P. Pravec, Ondrejov
Observatory; A. Leroy, Uranoscope de l'Ile de France, Gretz-Armainvilliers,
France; D. Baratoux, IRD, Geosciences Environnement Toulouse, Universite de
Toulouse; S. Bouley, Geosciences Paris-Saclay Laboratory, CNRS, Universite 
Paris-Saclay; and A. Rajaonarivelo, Observatory of Besely, Ecole du Monde, 
Madagascar, report that photometric observations taken with a 0.35-m telescope 
at the Sopot Observatory in Serbia and a 0.36-m telescope at Ecole du Monde 
Besely in Madagascar during Aug. 2-22 reveal that minor planet (25251) is a 
binary system with an orbital period of 13.005 +/- 0.004 hr.  The primary 
shows a period of 2.9973 +/- 0.0002 hr and has a lightcurve amplitude of 0.07 
magnitude at solar phases 5-10 degrees, suggesting a nearly spheroidal shape.  
Mutual eclipse/occultation events that are 0.07 magnitude deep indicate a 
lower limit on the secondary-to-primary mean-diameter ratio of 0.26.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2026 CBAT
2026 August 26                   (CBET 5731)              Daniel W. E. Green