4 ms·
White dwarfs are interesting because they make up almost all of the current or future outcomes of most stars in the milkyway. -> https://en.wikipedia.org/wiki/W
by _Microft 7y ago
White dwarfs are interesting because they make up almost all of the current or future outcomes of most stars in the milkyway. -> https://en.wikipedia.org/wiki/White_dwarf https://en.wikipedia.org/wiki/White_dwarf
The Roche-limit (the radius at which a satellite would be ripped apart) for the Sun-Earth system is at ~ 550000km. That's inside the current size of the Sun. So if the sun shrank a lot (white dwarfs are basically small, 'dead' stars which shrank to that size after the nuclear fusion stopped which had counteracted the attraction of the star's mass), Earth could actually be in such a low orbit and therefore fall apart due to the Sun remnant's attraction.
-> https://en.wikipedia.org/wiki/Roche_limit https://en.wikipedia.org/wiki/Roche_limit
- deleted 7y ago[deleted]
- prewett 7y agoWhy would a decrease in the sun's radius cause a change in Earth's orbit? From those to articles it sounds like the mass of the sun will remain about the same, so the orbit should remain about the same. And less mass will cause the orbit to migrate outwards.
- the8472 7y agoShrinking of the star simply makes it possible to come within the roche limit without being inside the star. The inspiral would happen due to separate processes e.g. friction as the star sheds its envelope or due to interactions between multiple planets.
- bigwavedave 7y agoWhen the Sun enters the red giant phase, will the radius have expanded enough to consume the earth? I'm trying to remember if that was something my physics professor said years ago or if I heard it from someone less reliable and am merely attributing it to him...
- _Microft 7y agoWikipedia says the sun is expected to expand out to roughly the orbit of Venus (consuming it and Mercury) and turning Earth into a blob of molten rock.