Electronic Telegram No. 533
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


(617) PATROCLUS
     F. Marchis and M. H. Wong, University of California at Berkeley;
and P. Descamps, J. Berthier, D. Hestroffer, and F. Vachier, Institut
de Mecanique Celeste et de Calcul des Ephemerides, Observatoire de
Paris, report the detection of a mutual event in the (617) Patroclus
binary Jupiter-trojan system (cf. IAUC 8666) using the Nickel 1-m
telescope at Lick Observatory.  During a 4-hr period of observation
starting on May 28.187 UT, the integrated photometry of the system
increased by 0.12 magnitude indicating an eclipse egress event between
(617) Patroclus I (Menoetius) and (617) Patroclus itself, in very good
agreement with the authors' recent predictions of mutual events.  The
authors request participation from observers at multiple longitudes
in order to refine the characteristics of the system.  Nights of
observations during events are scheduled on June 12 and 14 UT at Lick
observatory.  On June 27 and 29, the mutual events are scheduled to be
observed by the Spitzer telescope.  The system has a visual magnitude
of about 16.6.  At its current elongation of about 90 deg, the (617)
system can be only observed less than 4 hr per station.  Coordination
between observers is therefore necessary to maximize coverage of the
event lightcurves.  Details can be found at
http://astro.berkeley.edu/~fmarchis/Science/Asteroids/Patroclus/futur.html


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2006 CBAT
2006 June 2                      (CBET 533)               Daniel W. E. Green