Black Dwarf
Posted: Mon Mar 18, 2013 4:17 am
Here's a severely off-topic post for the off-topic section. Hope it will be considered within bounds...
harry dalek's signature says:
"Our sun has perhaps another 5 billion years before it becomes a red giant Some red dwarf stars will live trillions of years before they run out of fuel.
If the very first star in the universe was a red dwarf its still some where ."
As Harry says, red dwarf stars cool down very slowly. But what about after hundreds of billions of years or so, when they have cooled down to room temperature? Then, they would be to all intents and purposes 'black' but they would no longer be too hot to touch. So take a torch along if you want to 'walk on a star'. Only, because of the gravity, you may then get squashed into a thin layer of slime.
I've asked various astronomical authorities but no one seems prepared to answer what the surface of such a dead star would actually be like or even care - it's all too far in the future. They use terms like 'a cinder' or similarly unhelpful words.
It seems the atomic fusion process that drives stars generally ends with carbon. So would this cold surface be crystallised carbon say, effectively diamond dust, or perhaps there would be a diamond shell going miles down? Would such a shell be cracked or crazed? How high could any surface features be? Although the gravity would be crushingly strong, diamond is a pretty hard and unpersuadable material. But then maybe it would be super-smooth, like a billiard ball, the size of a small planet. Because of the strong gravity, it would probably be a pretty perfect sphere too.
Or would there be a diamond core surrounded by shells of lighter elements?
Active stars don't have solid surfaces but this would be different. I just am curious what the landscape of a spent star would look like.
Steve O
harry dalek's signature says:
"Our sun has perhaps another 5 billion years before it becomes a red giant Some red dwarf stars will live trillions of years before they run out of fuel.
If the very first star in the universe was a red dwarf its still some where ."
As Harry says, red dwarf stars cool down very slowly. But what about after hundreds of billions of years or so, when they have cooled down to room temperature? Then, they would be to all intents and purposes 'black' but they would no longer be too hot to touch. So take a torch along if you want to 'walk on a star'. Only, because of the gravity, you may then get squashed into a thin layer of slime.
I've asked various astronomical authorities but no one seems prepared to answer what the surface of such a dead star would actually be like or even care - it's all too far in the future. They use terms like 'a cinder' or similarly unhelpful words.
It seems the atomic fusion process that drives stars generally ends with carbon. So would this cold surface be crystallised carbon say, effectively diamond dust, or perhaps there would be a diamond shell going miles down? Would such a shell be cracked or crazed? How high could any surface features be? Although the gravity would be crushingly strong, diamond is a pretty hard and unpersuadable material. But then maybe it would be super-smooth, like a billiard ball, the size of a small planet. Because of the strong gravity, it would probably be a pretty perfect sphere too.
Or would there be a diamond core surrounded by shells of lighter elements?
Active stars don't have solid surfaces but this would be different. I just am curious what the landscape of a spent star would look like.
Steve O