3 ms·
"Barrow and Tipler estimate that it would take 10^15 years for a white dwarf to cool to 5 K;[11] however, if weakly interacting massive particles (WIMPs) exist,
by ordu 4y ago
"Barrow and Tipler estimate that it would take 10^15 years for a white dwarf to cool to 5 K;[11] however, if weakly interacting massive particles (WIMPs) exist, it is possible that interactions with these particles will keep some white dwarfs much warmer than this for approximately 10^25 years.[10]: §IIIE"[1]
Red dwarfs, I believe, can live for tens of trillions years, which is 10^13. And some of them will become white dwarfs.
[1] https://en.wikipedia.org/wiki/Black_dwarf https://en.wikipedia.org/wiki/Black_dwarf
- Maursault 4y agoA white dwarf is a dead star. The only light it emits is residual thermal energy. It may take a very long time to cool entirely, but in only millions of years it will effectively be so faint that it is invisible. Though a white dwarf was once a star, it is no longer when it reaches the white dwarf stage, because a star is defined as any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. A white dwarf has no energy source. Any remaining energy that it has is only remanent heat. White dwarfs do not shine; they glow. A red dwarf, on the other hand, will produce and emit light via hydrogen fusion for 10 trillion years or longer before burning out and becoming a dead star... or white dwarf, only faintly glowing for millions of years due to residual thermal energy. The last stars in the Universe will be red dwarfs, and even red dwarfs from the early Universe will continue to shine far, far longer, trillions of years longer, after all other stars have died.