Celestia Forums

There seem to be an awful lot of epistellar gas giant planets out there. As far as I have been able to find out, the best theory for their formation is that they migrated inwards from the outer regions of the planet-forming disk.

My question is, would it be possible to get an epistellar planet with the mass of Earth or Mars in this way, or would there not be enough drag on the planet to cause it to move inwards like this?

I thought 'epistellar' meant 'almost a star' - i.e. supermassive jovian worlds/brown dwarfs. But it seems you think it means 'star-hugging' - ie anything really close to the star.

Am I wrong?

The term is used at Extrasolar Visions to mean planets really close to their star. Also, if I remember my Greek lessons correctly, epi means "on", hence "on the star"... a planet which is almost on the star.

chaos syndrome wrote:The term is used at Extrasolar Visions to mean planets really close to their star. Also, if I remember my Greek lessons correctly, epi means "on", hence "on the star"... a planet which is almost on the star.

Fair enough - I stand corrected!
*Evil Dr G adds new word to vocabulary*

Thinking about it, I guess the brown dwarfs must be referred to as 'substellar objects', right? D'oh.

Evil Dr Ganymede wrote:*Evil Dr G adds new word to vocabulary*

But what a horrible word.

[pedantry]
It's a bastard mixture of Greek and Latin, for starters, but epi- also has no useful contrasting prefix apart from endo-, inside, which is obviously inappropriate here.
Better would have been peristellar, to be contrasted with apostellar for Jovians that remain in their region of formation. Or, if it was felt peristellar already had a useful, but more general, meaning assigned to it (as in "peristellar disc"), we could have had adstellar, with the potential for a contrasting abstellar.
Sigh. Words are too important to let scientists go around making them up on the spur of the moment ...
[/pedantry]

Grant