Electronic Telegram No. 320
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


(3169) OSTRO
     P. Descamps, Institut de Mecanique Celeste et de Calcul des
Ephemerides (IMCCE); and F. Marchis, University of California at
Berkeley -- in collaboration with with a group at Makes Observatory
in Reunion Island (A. Peyrot, J.-P. Teng-Chuen-Yu, J. Dorseuil, B.
Payet, T. Dijoux, Y. Leonie, H. Berrouachdi, C. Chion Hock, F. Benard,
C. Benard) and with J. Berthier, D. Hestroffer and F. Vachier, IMCCE
-- report that photometric observations of the minor planet (3169),
obtained on eight nights between Nov. 5 and Dec. 5, indicate that the
object is a binary system showing mutual eclipses and/or occultations.
The orbital period of the system is 0.2701 +/- 0.0002 day.  A regular
lightcurve of amplitude 0.35 mag is synchronized with the eclipse
events, indicating that at least one of the two bodies is elongated
and rotates synchronously with the orbital motion.  The sharp
eclipse/ occultation events occur at both rotational lightcurve minima
and have a duration of about 0.08 day and depth about 0.75 mag.
Additional observations of the eclipse/occultation events from more
than one station are desirable.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2005 CBAT
2005 December 20                 (CBET 320)               Daniel W. E. Green