Electronic Telegram No. 4206
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


(2343) SIDING SPRING
      J. Pollock, D. Caton, and R. Hawkins, Appalachian State University
(ASU); P. Pravec, Ondrejov Observatory; D. Pray, Sugarloaf Mountain
Observatory, South Deerfield, MA, U.S.A.; W. Cooney and J. Gross, Sonoita
Research Observatory, Sonoita, AZ, U.S.A.; D. Terrell, Southwest Research
Institute; J. Oey, Blue Mountains Observatory, Leura, NSW, Australia; V.
Benishek, Belgrade Astronomical Observatory; A. Galad and S. Gajdos, Modra
Observatory; R. Groom and K. Stranger, Perth Observatory; V. Chiorny, Kharkiv
Observatory; D. Reichart and J. Haislip, University of North Carolina at
Chapel Hill; and A. Smith, Gemini North, report that photometric observations
taken with a 0.35-m telescope at the ASU's Dark Sky Observatory (near Boone,
NC, USA), a 0.50-m telescope at the Sugarloaf Mountain Observatory, a 0.50-m
telescope at the Sonoita Research Observatory, a 0.35-m telescope at the Blue
Mountains Observatory, a 0.35-m telescope at the Sopot Observatory in Serbia,
a 0.60-m telescope at the Modra Observatory, a 0.36-m telescope at the Perth
Observatory, and a 0.70-m telescope at the Grakovo station of the Kharkiv
Observatory in Ukraine during Oct. 6-Nov. 21 reveal that minor planet (2343)
is a binary system with an orbital period of 11.789 +/- 0.003 hr.  The
primary shows a period of 2.10637 +/- 0.00008 hr, and has a lightcurve
amplitude of 0.15 mag at solar phases 2-15 degrees, suggesting a nearly
spheroidal shape.  Mutual eclipse/occultation events that are 0.04 to
0.06 magnitude deep indicate a lower limit on the secondary-to-primary
mean-diameter ratio of 0.19.  An additional brightness variation with a
period of 20.01 +/- 0.03 hr and an amplitude of 0.04 mag is present in
the observed lightcurve, that suggests a presence of a third body in the
system.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 December 1                  (CBET 4206)              Daniel W. E. Green