Electronic Telegram No. 239
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CBAT@CFA.HARVARD.EDU (science)
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(809) LUNDIA
     A. Kryszczynska, T. Kwiatkowski, R. Hirsch, M. Polinska, K.
Kaminski and A. Marciniak, Poznan Astronomical Observatory, report
that photometric observations obtained during Sept. 18-26 at Borowiec
Observatory show that (809) Lundia is a binary system with orbital
period of 15.4 hr.  Its lightcurve has a total amplitude of 1.1 mag
and it consists of a bi-modal synchronous rotation component with
amplitude about 0.35 mag and superimposed eclipses/occultations about
0.75 magnitude deep, suggesting that both components are of similar
sizes and that at least one of them is elongated and rotates
synchronously with the orbital motion.  From the system's absolute
magnitude (H = 12) and assuming a Vesta-like albedo for its V type
(Florczak et al. 2002, Icarus 159, 178), Kryszczynska et al. estimate
a mean diameter for each component of about 6 km.  Further observations
(photometric and/or direct imaging with the Hubble Space Telescope or
adaptive optics) are desirable.


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                         (C) Copyright 2005 CBAT
2005 October 1                   (CBET 239)               Daniel W. E. Green