Electronic Telegram No. 957
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


(1830) POGSON
     D. Higgins, Canberra, Australia; P. Pravec and P. Kusnirak, Ondrejov
Observatory; J. Oey, Leura, N.S.W., Australia; and D. Pray, Carbuncle Hill
Observatory, Greene, RI, report that photometric observations obtained
during Apr. 18 to May 9 reveal that minor planet (1830) is a binary system
with an orbital period of 24.240 +/- 0.005 hr.  The primary shows a period
of 2.5702 +/- 0.0001 hr, and it has a lightcurve amplitude of 0.12 mag.
Mutual eclipse/occultation events that are 0.08- to 0.22-mag deep indicate
a lower limit on the secondary-to-primary mean-diameter ratio of 0.32.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 May 10                      (CBET 957)               Daniel W. E. Green