时命名为）2003 UN313三个天体。预计在未来的数月和数年，国际天文学联合会（IAU）将宣布更多的“矮行星”。现在有一打的侯选“矮行星”列在.IAU的“矮行星”监视表上，当发现新天体和更了解已存侯选者的物理性质时，监视表会更改。
认识到“矮行星”冥王星作为新的一类“海（王星）外天体”或“冥族天体”的重要原型，国际天文学联合会将建立一种程序来命名这些天体。
附件一：原文
IAU 2006 General Assembly: Result of the IAU Resolution votes24. August 2006, Prague ……six IAU Resolutions were also passed at the Closing Ceremony of the General Assembly:
5.Resolution 5A: "Definition of 'planet' "
6.Resolution 6A: "Definition of Pluto-class objects"
The IAU members gathered at the 2006 General Assembly agreed that a "planet" is defined as a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
This means that the Solar System consists of eight "planets" Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new distinct class of objects called "dwarf planets" was also decided. It was agreed that "planets" and "dwarf planets" are two distinct classes of objects. The first members of the "dwarf planet" category are Ceres, Pluto and 2003 UB313 (temporary name). More "dwarf planets" are expected to be announced by the IAU in the coming months and years. Currently a dozen candidate "dwarf planets" are listed on IAU's "dwarf planet" watchlist, which keeps changing as new objects are found and the physics of the existing candidates becomes better known.
The "dwarf planet" Pluto is recognised as an important proto-type of a new class of trans-Neptunian objects. The IAU will set up a process to name these objects.
据第26届IAU大会的网站（D I S S E R T A T I O C V M-NVNCIO SIDEREO III-P R A G A E- M M V I- 2 4 . V I I I .），IAU大会关于太阳系行星定义的决议最终稿包含4个部分：5A号决议，5B号决议，以及6A号决议，6B号决议。投票将分开来依次进行。实际上，只通过了5A号决议和6A号决议，而否决了5B号和6B号决议.
IAU决议：太阳系内一颗行星的定义
当代的观测正在改变着我们对行星系统的认识，重要的是，我们对天体的命名反映我们目前的认识。这特别是用于“行星”这个称号。“行星”一词原先表述的是几颗在星空背景移动的“游荡星”。近来的发现导致我们需要用现有科学信息创立一个新的定义。
决议5A
IAU决定我们太阳系内的行星和其它天体按照下列方式定义为3个明确的类别：
(1)一个行星1是这样的一个天体：(a)它在环绕太阳的轨道上运行；（b）它有足够大的质量，靠自身引力克服各种刚性的彻体力，以致呈现一种流体静力平衡（几乎圆球）形状；（c）它清除了其轨道周围的区域。
(2)一个矮行星是这样的一个天体：(a)它在环绕太阳的轨道上运行；（b）它有足够大的质量，靠自身引力克服各种刚性的彻体力，以致呈现一种流体静力平衡（几乎圆球）形状；（c）它没有清除其轨道周围的区域。 同时(d)不是一颗卫星。
(3)其它环绕太阳运行的天体3 ，除了卫星之外，统称为“太阳系小天体”。
1 八个行星是：水星、金星、地球、火星、木星、土星、天王星、海王星。
2 IAU将建立一个IAU程序来界定天体属于矮行星还是其它类别。
3 目前这些天体包括大多数的太阳系小行星，大多数的海（王星）外天体（TNOs），彗星，和其它小天体。
决议5B
在决议5A第一节和脚注1的“行星”前面插入“经典”。即：
(1)一颗经典行星4是这样一个天体……
IAU决议：冥王星
决议6A
IAU进一步决定：
按照上面的定义冥王星是一颗矮行星，并作为海（王星）外天体中一个新类别的原型。
决议6B
下面的语句加入到决议6A中：这类天体称为“plutonian objects”。
附录：原文
IAU Resolution: Defi nition of a Planet in the Solar System
Contemporary observations are changing our understanding of planetary systems, and it is important that our nomenclature for objects refl ect our current understanding. This applies, in particular, to the designation ‘planets’. The word ‘planet’ originally described ‘wanderers’ that were known only as moving lights in the sky. Recent discoveries lead us to create a new defi nition, which we can make using currently available scientific information.
Resolution 5A
The IAU therefore resolves that planets and other bodies in our Solar System be defi ned into three distinct categories in the following way:
(1) A planet1 is a celestial body that (a) is in orbit around the Sun, (b) has suffi cient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit
(2) A dwarf planet is a celestial body that (a) is in orbit around the Sun, (b) has suffi cient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects3 orbiting the Sun shall be referred to collectively as “Small Solar System Bodies”.
1 The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2 An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
3 These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.
Resolution 5B
Insert the word “classical” before the word “planet” in Resolution 5A, Section (1), and footnote 1. Thus reading:
(1) A classical planet1 is a celestial body . . .
IAU Resolution: Pluto
Resolution 6A
The IAU further resolves:
Pluto is a dwarf planet by the above defi nition and is recognized as the prototype of a new category of trans-Neptunian objects.
Resolution 6B
The following sentence is added to Resolution 6A: This category is to be called “plutonian objects.”
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