Talk:Supergiant planet
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[edit] Definition Problems
This article is confusing to a layman, and needs the attention of an expert. Specifically, what is the definition of "largest cold mass"? Noclevername 10:26, 7 December 2006 (UTC)
- A "cold body" is either a body that does not generate energy, or a body that does not generate energy by fusion. The first definition would exclude the Earth, since it generates energy by radioactive decay, so it is clear that the second definition is what is meant in this article. A planet and a white dwarf both fit this definition. The radius of a cold body is a bimodal function of its mass (composition and temperature being held equal), that is, as mass increases, radius increases, and then decreases. For example, the more massive a white dwarf is, the smaller its radius. The term "largest cold mass" denotes that mass at which the radius of a cold body is maximum. The value may depend on composition or temperature. Asimov and Dole, in Planets for Man, claimed that Jupiter has that maximum radius, more or less. But since then, it's been discovered that 51 Peg b, a transiting planet, has mass considerably less than Jupiter and radius considerably greater. This could be due to insolation, since 51 Peg b is very close to its star. If Asimov were right, any planet more massive than Jupiter would be a supergiant, by the definition given in the article. Vegasprof 11:25, 31 March 2007 (UTC)
Not only is this confusing, it's directly contradictory of itself. Rossheth 18:50, 7 December 2006 (UTC)
- I do not believe that any authoritative source has defined the word ``supergiant planet``, although the term has been used in a few scholarly publications. (Unlike the term supergiant star which has an accepted definition.) Vegasprof 11:25, 31 March 2007 (UTC)
