AST 309 Lecture Notes - Lecture 17: Beryllium-10, Stellar Magnetic Field, Half-Life
Document Summary
70-90% of all young stars within 6000 light years of the sun formed within rich embedded clusters. Of these clusters, 75% contain massive (o and b) stars. The other 25% may have previously contained massive stars, but they are no longer there because they may have already undergone supernova. Conclusion: the majority of stars, even low mass stars like the sun, form in clustered environments, not in isolation. However, young open clusters usually disperse after a few million to a few. Massive o and b stars have short lifetimes (few million to 10"s of millions of years). Stars like sun live for 10 billion years on ms. take 30-40 million years to evolve onto ms. Low mass take longer to evolve onto ms than high mass. Produce higher metallicity elements, which will be ejected back into ism after supernova. The products of short-lived radio nuclides (slrs) have been found to be present in meteorites.
