“The nuclear reactions in the cores of these stars will burn through these supplies in only millions of years.”
How can some stars only last a few millions of years, but many stars last many billions of years?
The candle that burns twice as bright lasts half as long.....................
How can some stars only last a few millions of years, but many stars last many billions of years?
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Size matters.
The smaller you are the more longevity you have.
Some red dwarves will burn their fuel efficiently over TRILLIONS of years.
Blue giants gobble up their gas with maximum inefficiency and only last millions.
But that’s good. When they explode, they scatter metals.
Depends on their mass. High mass stars burn "blue hot". Our sun is a yellow, much cooler star.
Some of those Galaxies had big 390 engines which were fuel suckers.