[ETL]

How can some stars only last a few millions of years, but many stars last many billions of years?

Depends on their mass. High mass stars burn "blue hot". Our sun is a yellow, much cooler star.

[plsvn]

How can some stars only last a few millions of years, but many stars last many billions of years?

Depends on their mass. High mass stars burn "blue hot". Our sun is a yellow, much cooler star.

Probably should add that hotter stars burn through their fuel faster than cooler stars so the cooler stars are around alot longer than the hotter ones.

[jpsb]

IIRC hotter stars (like our sun) only “burn” their core where as cooler stars burn all of their hydrogen do to convention. The good news is when the hotter star nova they seed their surroundings with more hydrogen and heavier elements. Our sun will not nova but as a Red Giant it to will release it’s hydrogen via interstellar wind. Only the hot core will remain as a white dwarf.