How old is a yellow star?

Answer 1

It can be as old as 10 billion years. Then it increases to the size of a giant and supernova. After that it turns into a small dense white dwarf.

Answer 2

A typical yellow star, like the Sun, has a lifespan of about 10 billion years. The Sun is currently about 4.6 billion years old, so a yellow star can be around that age or older.