Why do astronomers need to study a group of stars rather than just one or two?
The more stars they study, the more information they get about how stars form, how they evolve, and how they change over time. If they just studied one star, all we find out is about that one star which may or may not be similar to our own sun or other stars. If you want to study trees, you study as many different species over time as you can. You don’t just pick one oak tree to study and assume it tells you everything you need to know about all trees.
