The new planet definition.

[nc-1701]

I actualy like the new planet definition very specific and explicit.

The only place for confusion is that it states that a planet is an object orbiting its star that is round due to its gravity, clears its orbit, and IS NOT A STAR.

Now we need a fool proof definition of star. Any ideas I'm coming up empty. This makes classifying a planet look so easy.

 

[emzie]

I actualy like the new planet definition very specific and explicit.

The only place for confusion is that it states that a planet is an object orbiting its star that is round due to its gravity, clears its orbit, and IS NOT A STAR.

Now we need a fool proof definition of star. Any ideas I'm coming up empty. This makes classifying a planet look so easy.

A mass capable of sustaining nuclear fusion, or at one time was able to do this.

 

[nc-1701]

Then Jupiter is a Star!?

 

[deo]

A star is easy to define, its an object that is able to fuse Hydrogen.

 

[deo]

Then Jupiter is a Star!?

Jupiter is not able to do nuclear fusion.

Brown Dwarfs are a problem through

 

[emzie]

Then Jupiter is a Star!?

Fine, massive enough to burn deuterium.

 

[SS-18 ICBM]

I actualy like the new planet definition very specific and explicit.

The only place for confusion is that it states that a planet is an object orbiting its star that is round due to its gravity, clears its orbit, and IS NOT A STAR.

Now we need a fool proof definition of star. Any ideas I'm coming up empty. This makes classifying a planet look so easy.

I'm happy with the definition too. I cringed at the thought of Charon as a planet during the preliminary discusiions of the IAU.

Definition of star? Any body containing hydrogen undergoing nuclear fusion causing it to shine.

 

[Perfection]

Okay first to linklist!

The other threads on the IAU redifiniton:
http://forums.civfanatics.com/showthread.php?t=183682
http://forums.civfanatics.com/showthread.php?t=183588
http://forums.civfanatics.com/showthread.php?t=183524
http://forums.civfanatics.com/showthread.php?t=182968
http://forums.civfanatics.com/showthread.php?t=182220
A recent debate thread:
http://forums.civfanatics.com/showthread.php?t=175845
My proposed definition scheme:
http://forums.civfanatics.com/showpo...9&postcount=24

Old semi-relevant threads:
Size of the Planets, A Comparison
http://forums.civfanatics.com/showthread.php?t=175804
Astronomy Picture thread
http://forums.civfanatics.com/showthread.php?t=61837
What is a planet?
http://forums.civfanatics.com/showthread.php?t=130544
Tenth Planet Has A Moon
http://forums.civfanatics.com/showthread.php?t=130437
The 12th Planet (funny!)
http://forums.civfanatics.com/showthread.php?t=98113
tenth planet?
http://forums.civfanatics.com/showthread.php?t=81976



I should not that while I by and large like the definition have two small quibbles:
The first one is nicely outline here:
http://forums.civfanatics.com/showpost.php?p=4446749&postcount=37
The second is the term "dwarf planet" this should be made into a single word descrition

As for the definition of a star I'd claim that a star is a body that fuses hydrgen or any heavier element (excluding dueterium). Brown dwarfs are bodes that are capable of fusing dueterium nut not any other isotope. And stellar remnants are compact bodies that were at one point stars. A planet can orbit a star, brown dwarf or stellar remanant. I might put some qualifiers for planets being able to orbit certain brown dwarf systems due to the fact that low-mass brown dwarves share properties with both stars and Jovians.