Electronic Telegram No. 4356
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


(2486) METSAHOVI
     D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
P. Pravec, H. Kucakova, K. Hornoch and P. Kusnirak, Ondrejov Observatory;
W. Cooney and J. Gross, Sonoita Research Observatory, Sonoita, AZ, U.S.A.;
D. Terrell, Southwest Research Institute; and N. Gaftonyuk, Crimean
Astrophysical Observatory, 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 0.50-m telescope at the Sonoita Research
Observatory, and a 1.0-m telescope at the Crimean Astrophysical Observatory
during 2016 Nov. 1-Dec. 29 reveal that minor planet (2486) is a binary
system with an orbital period 172.6 +/- 0.2 hr.  The minor planet was
suspected to be a binary system from photometric observations taken from
2006 to 2014 (see CBET 860; Pravec et al. 2016, Icarus 267, 267) that
showed the presence of two additive rotational lightcurves.  The two
rotational lightcurves are present also in the 2016 data, and they have
periods of 4.4521 +/- 0.0001 and 2.64040 +/- 0.00005 hours and amplitudes
of 0.11 and 0.03 mag, respectively.  There are superimposed
eclipse/occultation events that are 0.08- to 0.12-magnitude deep,
indicating a lower limit on the secondary-to-primary mean-diameter ratio
of 0.28.  The mean absolute R magnitude in the Cousins system is
H_R = 12.39 +/- 0.04, with the phase relation slope parameter
G = 0.41 +/- 0.05.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2017 CBAT
2017 February 9                  (CBET 4356)              Daniel W. E. Green