Posted: Jan 04, 2017 2:44 pm
by DavidMcC
Cito di Pense wrote:
DavidMcC wrote:There is one way an extrasolar planet can have an oxygen atmosphere without life:

How would a planet orbiting a white dwarf still have an atmosphere of any kind? I'm assuming that star has already been through the red giant stage of its evolution.

I suppose it depends on the detailed history of that particular system. Do you have any reason to suppose that there couldn't be an atmosphere on such a planet. If the star is in the main sequence and the planet is far enough away from the star, then I don't see why it couldn't hang on to at least some atmosphere.

EDIT: I suppose that the mere fact that it is an oxygen white dwarf makes it not a main sequence star straight away, doesn't it?