Celestia Forums

My scenario: An old white dwarf, twice the size of earth due to low mass, cooled down to 5000k. A habitable planet at just the right distance (temperature-wise), with a high precession rate of it's axis from being pulled around by intense gravity.

My question: Is this possible? Why or why not?

Of course, we'll ignore the stellar evolution of the host star. The planet you speak of would not have survived the giant phase of it's star.

I think white dwarfs put out some excess UV radiation, but I'm not sure on that. Anyone here, feel free to correct me. Other than (perhaps) that, I don't see why not (again, ignoring stellar evolution).

I once heard that a quasar or something like that had it's own planets, so perhaps a planet can form after the star sheds its layers.

And about the radiation, I read in a scientific american snippet that white dwarves emit enough radiation to slice atoms apart and create haze on the surface of a rock planet or something like that. So I'm assuming that a cooled-down white dwarf emits less radiation.

If a planet could capture a hunk of rock and end up making it a moon, couldn't a star capture something (larger) wandering also and make it a planet? That would eliminate the situation of stellar evolution... yes?

LordFerret wrote:If a planet could capture a hunk of rock and end up making it a moon, couldn't a star capture something (larger) wandering also and make it a planet? That would eliminate the situation of stellar evolution... yes?

Indeed. It would then take a long, long time for the planet to become habitable again. Luckily, white dwarfs tend to last a while.

Hungry4info wrote:Luckily, white dwarfs tend to last a while.

Yeah, I read on some site depicting the sun's lifetime that stated the sun as a white dwarf will take 25 trillion years to cool to a mini red dwarf and then an additional 75 trillion more years to cool down to a dead black dwarf body. Talk about long lasting! Later!

J P