Electronic Telegram No. 4346
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


(6186) ZENON
     V. Benishek, Belgrade Astronomical Observatory; P. Pravec, Ondrejov
Observatory; N. Gaftonyuk, Simeiz Observatory; M. Husarik and G. Cervak,
Skalnate Pleso Observatory; and J. Oey, Blue Mountains Observatory, Leura,
NSW, Australia, report that photometric observations taken with a 0.35-m
telescope at the Sopot Observatory in Serbia, a 1.0-m telescope at the Simeiz
Observatory, a 0.61-m telescope at the Skalnate Pleso Observatory, and a
0.35-m telescope at the Blue Mountains Observatory during 2016 Oct. 31-2017
Jan. 1 reveal that minor planet (6186) is a binary system with an orbital
period of 14.392 +/- 0.004 hr.  Mutual eclipse/occultation events that are
0.08- to 0.16-magnitude deep indicate a secondary-to-primary mean-diameter
ratio of 0.28 +/- 0.03.  The eclipsing/occulting secondary has a synchronous
rotation with an observed lightcurve amplitude of 0.04 mag.  Superimposed to
the eclipse/occultation lightcurve are two rotational lightcurves with
periods 2.6832 +/- 0.0002 hr and 3.2981 +/- 0.0002 hr, each with an amplitude
of 0.08 mag; their behavior in the mutual events -- they are present with
unchanged shapes during the events -- indicates that none of them belongs to
the eclipsing/occulting secondary.  This suggests that, while one of the
short periods belongs to the primary, the other belongs to a third body in
the system (compare with other cases of this kind in Pravec et al. 2016,
Icarus 267, 267).


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2017 CBAT
2017 January 14                  (CBET 4346)              Daniel W. E. Green