Do you think this star is older or younger than the Sun? How do you know it?

I observe a star that is freely floating in space and is not part of any star cluster. This star is a K type red giant, and when i observe its spectrum, its chemical composition is similar to the stars in a globular cluster.



What do you think is the origin of this star, that is, what type of system was it a part of when it formed?Do you think this star is older or younger than the Sun? How do you know it?If a K and already a red giant, then it is much older than our sun. Our Sun (G2) is expected to remain on the main sequence for 10 billion years before turning into a red giant; a K-star should be expected to last even longer.



The sun is only 5 billion years old and your star is at least 11 billion years old (maybe a lot more if it is a "later" K, like K7 or K8)



So this stars was born at least 6 billion years before the sun; could be 10 billion years before.



The chemical composition being the same as stars in globular clusters , which normally means a star with less "metals" (astronomers call "metal" any element with a bigger nucleus that Lithium). This would make it a star that was born when the universe was much younger (there was a lot less "metal" in the interstellar clouds).



Combining the two elements, it sounds like a star that was born one generation before our Sun; it may even be a star from the early days of our Galaxy.



This makes it likely that it was born in a globular cluster and was later expelled, due to the gravitational interference from the other stars in the same cluster.Do you think this star is older or younger than the Sun? How do you know it?I would say it just started off as a normal star e.g.a cloud of dust and gas.

And has now eveloved into a red giant due to compression and extensive heat expelled from its core.Do you think this star is older or younger than the Sun? How do you know it?It is a Population 2 star, that means its very ancient, probably formed about 10 billion years ago, as are globular clusters, which are conglomerations of Pop 2 stars held together by gravitational attraction.



As for the system it was a part of, it would have formed in what is now the central bulge of the galaxy as part a gigantic rotating cloud of hydrogen.gas.Do you think this star is older or younger than the Sun? How do you know it?
The fact that is spectral type K can't be used to infer age, as it no doubt was a different spectral type while on the main sequence. But a chemical composition similar to the stars in a globular cluster implies low metallicity, which means it is a Population II star, formed from a relatively pristine gas cloud of hydrogen and helium much earlier in the history of the universe. That would put its likely age at around 10 or 12 billion years, similar to the ages of globular clusters in our galaxy and more than twice as old as the Sun. It might have formed as part of an open cluster, or it may have been expelled from a globular.



The Sun is a Population I star, formed after many earlier stars had gone supernova, seeding the galaxy with heavier elements, collectively referred to as "metals".