> "But either way, as stars go, [a few hundred thousand to a couple million years is] not a lot. Our own Sun will outlive multiple generations of such giants, and red dwarfs, the smallest stars in the universe, can stretch for trillions of years at a time. In fact, just a fun side note, red dwarfs live for so long that the entire universe isn't even old enough for them to start dying yet."
A little bit off base there.
The sun is going to eventually turn into a white dwarf. White dwarfs are indefinitely stable; our sun is going to stick around, in some form, for roughly 10^15 years as an energy-emitting body, and for far longer than that as a cold "black" dwarf. After some 10^1500 years, it'll probably turn into a lump of iron, as the only indefinitely stable isotope is 56Fe, and all other elements will eventually turn into 56Fe via quantum tunneling.
Our sun is going to change form, but it's among the longest-lived things in the cosmos.
Neutron stars also have no expiry date. Once they're stable, they barely even cool down. The only thing that can kill them is proton decay (not likely) or if they're in a busy neighborhood and absorb enough interstellar gas to push them into black hole mass territory. They're effectively eternal.
Anyway, it's nice that Betelgeuse isn't going to harm life on Earth.
A little bit off base there.
The sun is going to eventually turn into a white dwarf. White dwarfs are indefinitely stable; our sun is going to stick around, in some form, for roughly 10^15 years as an energy-emitting body, and for far longer than that as a cold "black" dwarf. After some 10^1500 years, it'll probably turn into a lump of iron, as the only indefinitely stable isotope is 56Fe, and all other elements will eventually turn into 56Fe via quantum tunneling.
Our sun is going to change form, but it's among the longest-lived things in the cosmos.
Neutron stars also have no expiry date. Once they're stable, they barely even cool down. The only thing that can kill them is proton decay (not likely) or if they're in a busy neighborhood and absorb enough interstellar gas to push them into black hole mass territory. They're effectively eternal.
Anyway, it's nice that Betelgeuse isn't going to harm life on Earth.