Electronic Telegram No. 1715
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://www.cfa.harvard.edu/iau/cbat.html


(2577) LITVA
     B. D. Warner, Palmer Divide Observatory and Space Science Institute,
Colorado Springs, CO, U.S.A.; P. Pravec, Ondrejov Observatory; A. W. Harris,
Space Science Institute, La Canada, CA, U.S.A.; D. Higgins, Hunters Hill
Observatory, Ngunnawal, ACT, Australia; C. Bembrick, Mt. Tarana Observatory,
Bathurst, NSW, Australia; and J. Brinsfield, Via Capote Observatory, Thousand
Oaks, CA, U.S.A. report that photometric observations obtained during Feb.
28-Mar. 8 reveal that minor planet (2577) is a binary system with an orbital
period of 35.78 +/- 0.05 hr.  The primary shows a period of 2.8141 +/- 0.0006
hr, and it has a lightcurve amplitude of 0.24 mag.  Mutual eclipse/occultation
events indicate a secondary-to-primary mean-diameter ratio of 0.35 +/- 0.02.
The periods and amplitudes were determined using a subset of data (Mar. 4-8).
Data on Feb. 28 and Mar. 1 show no events and fit the same primary period, but
the lightcurve has a slightly different shape; this may indicate that the
primary lightcurve is evolving with changing viewing aspect, and so additional
observations are warranted as the moon clears the area.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2009 CBAT
2009 March 11                    (CBET 1715)              Daniel W. E. Green