Das IAU Komitee präsentierte heute in Prag die neuen Vorschläge zur Planeten-Definition
Update 24. 8.: Endgültige Version der IAU Resolution ist jetzt online!
Final Version of Resolution on the Definition of a Planet
IAU Resolution: Definition of a Planet in the Solar System
Dissertatio cum Nuncio Sidereo III, No. 9 - August 24, 2006, Seite 8
Update: 23. 8.: Resolution 5 Entwurf c
Hier der Text der heute vor der Diskussion und Information ausgeteilt wurde.
Die abschließende Testabstimmung brachte folgendes Ergebnis:
RES 5: 70% Nein
RES 6: 80% Nein
RES 7: 80% Nein
Modified IAU draft for the Resolution 5 , Planet Definition
Prague, August 22nd, 12h30 , Copied from handout at the
IAU Resolution: Definition of a Planet
Contemporary observations are changing our understanding of
planetary systems, and it is important that our nomenclature
objects reflects our current understanding. This applies, in
particular to the designation 'planets'. The word 'planet'
described 'wanderers' that were known only as moving lights
in the sky.
Recent discoveries lead us to create a new definition, which
make using currently available scientific information. (Here
not concerned with the upper boundary between 'planet' and
nor the distinction between stars and brown dwarfs).
The IAU therefore resolves that planets and other bodies in
systems be defined in the following way:
(1) A planet is a celestial body that (a) has sufficient
mass for its self-
gravity to overcome rigid body forces so that is assumes a
equilibrium (nearly round) shape, and (b) is in orbit
around a star, and
is neither a star or a satellite of a planet.
(2) In our Solar System we distinguish between the eight
as the dominant objects in their local population zones, and
which are not.
(3) All natural non-planet objects orbiting the Sun,
includind most of the Solar System asteroids, near-Earth
Mars-, Jupiter-, Neptune-Trojan asteroids, most Centaurs,
Trans-Neptunian Objects (TNOs), and comets, shall be referred
to collectively as "Small Solar System Bodies". In the new
nomenclature the term "minor planet" is not used.
 This generally applies to objects with mass above 5 x
10^20 kg and diameter
greater than 800 km. An IAU process will be established to
candidates near this boundary.
The IAU further resolves:
Pluto is a dwarf planet by the above scientific definition,
as are one or
more recently discovered large trans-Neptunian objects. In
the classical planets, these objects have orbital periods in
excess of 200
years and typically have highlx inclined orbits with large
designate this category of planetary objects, of which Pluto
is the prototype,
as a new class that we call 'XXXXX'. We propose that the MPC
create an new
and separate catalog for these objects and their orbital
Pluto as the first entry.
Where, XXXXX = Or, ...
plutons Tombaugh Objects
plutoids Tombaugh Planets
plutinos (already used)
The IAU further resolves:
For two or more objects comprising a multiple object system,
primary object is designated a planet if it independently
definition of a planet. As secondary object satiesfying
is also designated a planet if over most of the orbital
period the system's
center of gravity resided outside the primary. Secondary
satiesfying these criteria are satellites.
Vorschlag für neue Planeten - Definition der IAU
22. August 2006/Günther Wuchterl