Electronic Telegram No. 5727
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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(6543) SENNA
      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 Aug. 6-21 reveal that 
minor planet (6543) is a binary system with an orbital period of 13.82 +/- 
0.01 hr.  The primary shows a period of 3.3063 +/- 0.0001 hr and has a 
lightcurve amplitude of 0.18 magnitude at solar phases 3-7 degrees,
suggesting a nearly spheroidal shape.  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      superseded by text appearing later in the printed IAU Circulars.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 2026 CBAT
2026 August 25                   (CBET 5727)              Daniel W. E. Green