How Old Are Third Generation Stars

[plat]

In our galaxy?

 

[nexium]

It is generally thought that our galaxy formed from a very large nebula ten billion years ago, so some first generation stars formed ten billion years ago. A few of these were class O, B and A stars that go super nova in about a million years. <br /> Second generation stars formed from the super nova reminents and a few of these were O, B and A. These quickly went supernova, followed briefly by third generation stars, which likely were a millionth part of the total stars in our galaxy 9.99 billion years ago. At present about 1% percent of the stars in our galaxy are third generation stars, with smaller percentages forth, fifth, sixth and higher generation. Nearly all of the class M stars, are still main sequence, plus perhaps 80% of the class K stars. These low mass stars are much more numerious than the very hot short life stars. Perhaps someone can make better guesses than mine on the percentages. Average third generation stars are perhaps four billion years old, but there are not many of them. Some are 9.99 billion years old and at least one was born today. <br /> Are G2 stars brighter and more massive than G9 stars? Neil