Electronic Telegram No. 4327
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)
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Prepared using the Tamkin Foundation Computer Network


(5872) SUGANO
     D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
P. Pravec, K. Hornoch, and P. Kusnirak, Ondrejov Observatory; A. Carbognani,
Astronomical Observatory of the Aosta Valley Autonomous Region, Italy; Yu. N.
Krugly and V. Chiorny, Kharkiv Observatory; R. Inasaridze, V. Ayvazian, and
O. Kvaratskhelia, Abastumani Observatory; M. Husarik and M. Pikler, Skalnate
Pleso Observatory; V. Benishek, Belgrade Astronomical Observatory; and I.
Molotov, Keldysh Institute of Applied Mathematics, Moscow, report that
photometric observations taken with a 0.50-m telescope at the Sugarloaf
Mountain Observatory, a 0.65-m telescope at the Ondrejov Observatory, a
0.81-m telescope at the Observatory of the Aosta Valley Autonomous Region, a
0.70-m telescope at the Chuguev station of the Kharkiv Observatory in
Ukraine, a 0.70-m telescope at the Abastumani Observatory, a 0.6-m telescope
at the Skalnate Pleso Observatory, and a 0.35-m telescope at the Sopot
Observatory in Serbia during 2016 Sept. 23-Oct. 2 reveal that minor planet
(5872) is a binary system with an orbital period of 18.04 +/- 0.02 hr.  The
primary shows a period of 3.3642 +/- 0.0002 hr and has a lightcurve amplitude
of 0.11 mag at solar phases 15-20 degrees, suggesting a nearly spheroidal
shape.  Mutual eclipse/occultation events that were 0.04- to 0.12-magnitude
deep indicate a lower limit on the secondary-to-primary mean-diameter ratio
of 0.30.  The event depth progressively decreased during the observational
interval, indicating that the system moved away from the eclipse geometry.
Additional observations taken during Oct. 3-8 showed that the mutual events
disappeared.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2016 CBAT
2016 October 11                  (CBET 4327)              Daniel W. E. Green