barx1963
19-05-2011, 07:07 PM
Just heard a report on the ABC Radio News on a newly reported discovery of 10 planets that have been located that are not orbiting a star.
2 points that sprung to mind.
1. Can they really be called planets? Given the definition of planet that was used to define Pluto a a dwarf planet, by deinition a planet has to orbit a star.
2. The report seemed to suggest they are orphan planets, which would imply that they once had a parent star and had been ripped away. Of course they may have formed as lower mass brown dwarf style objects without a parent star, in which case the "orphan" tag is not correct.
I am probably just being pedantic, but that's just me!
Malcolm
2 points that sprung to mind.
1. Can they really be called planets? Given the definition of planet that was used to define Pluto a a dwarf planet, by deinition a planet has to orbit a star.
2. The report seemed to suggest they are orphan planets, which would imply that they once had a parent star and had been ripped away. Of course they may have formed as lower mass brown dwarf style objects without a parent star, in which case the "orphan" tag is not correct.
I am probably just being pedantic, but that's just me!
Malcolm