Electronic Telegram No. 4794
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
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Prepared using the Tamkin Foundation Computer Network


(2171) KIEV
     D. Romeuf, Chapdes-Beaufort, Lyon 1 University, France; D. Augustin,
Anglet, France; R. Behrend, Geneva Observatory, Switzerland; V. Benishek,
Belgrade Astronomical Observatory; P. Pravec, Ondrejov Observatory; B.
Christmann, J. Michelet, and R. Montaigut, Club d'Astronomie de Lyon Ampere,
France; E. Barbotin, Etriac, France; P. Sogorb, La Bastide des Jourdans,
France; R. Durkee, Shed of Science South Observatory, Pontotoc, TX, U.S.A.;
F. Manzini, Stazione Astronomica di Sozzago, Italy; and F. Sold, Observatorio
Amanecer de Arrakis, Sevilla, Spain, report that photometric observations
taken with a 0.36-m telescope at Pommier Observatory in France, a 0.14-m
refractor at "Deep Sky Chile" observatory in Chile, a 0.35-m telescope at the
Sopot Observatory in Serbia, a 0.28-m telescope at the La Souchere Observatory
in France, a 0.50-m telescope at the La Grande Vallee Observatory in France, a
0.28-m telescope at the Bastidan Observatory in France, a 0.50-m telescope at
the Shed of Science South Observatory, a 0.40-m telescope at the Stazione
Astronomica di Sozzago, and a 0.20-m telescope at the Observatorio Amanecer de
Arrakis during Apr. 15-June 2 reveal that minor planet (2171) is a binary
system with an orbital period of 22.96 +/- 0.01 hr.  The primary shows a
period of 3.1716 +/- 0.0002 hr and has a lightcurve amplitude of 0.11 mag at
solar phases 6-7 degrees, suggesting a nearly spheroidal shape.  Mutual
eclipse/occultation events that are 0.06 to 0.12 magnitude deep indicate a
lower limit on the secondary-to-primary mean-diameter ratio of 0.24.  The
secondary appears synchronous and has a light-curve amplitude (in the combined
primary-plus-secondary light curve) of 0.02-0.03 mag, suggesting a moderately
elongated shape with an equatorial-axis ratio of 1.3.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2020 CBAT
2020 June 10                     (CBET 4794)              Daniel W. E. Green