Electronic Telegram No. 504
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html


(1717) ARLON
    W. Cooney, J. Gross, and D. Terrell, Sonoita Research Observatory,
Sonoita, AZ; P. Pravec and P. Kusnirak, Ondrejov Observatory; D. Pray,
Carbuncle Hill Observatory, Greene, RI; Yu. Krugly, Kharkiv Observatory;
L. Kornos, J. Vilagi, S. Gajdos, and A. Galad, Modra Observatory;
V. Reddy, Department of Space Studies, University of North Dakota,
Grand Forks; R. Dyvig, Quinn, SD; S. Nudds, Elginfield Observatory,
University of Western Ontario; and Z. Kanuchova, M. Pikler,
and M. Husarik, Skalnate Pleso Observatory, report that photometric
observations obtained during Feb. 24-Apr. 17 confirm that the system is
binary.  Mutual events (satellite occultation and eclipse behind the
primary, as well as transits of the satellite and its shadow over the
primary) were observed to be repeating with a synodic orbital period of
117.0 hr.  The two linearly additive components with periods of 5.148
and 18.23 hr (initially reported on CBET 369) are still present, and
they are interpreted as rotation lightcurves of the components of the
binary system.  Depths of the observed attenuations put a lower limit
on a secondary-to-primary mean-diameter ratio of 0.5.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2006 CBAT
2006 May 6                       (CBET 504)               Daniel W. E. Green