Stellar isochrone

Okay kiddo, let's imagine you have a bunch of stars together in one group, like a big family. Now, some of those stars may be older or younger than others, just like some people in a family are older or younger than their siblings, right?

Well, scientists like to study these groups of stars and figure out how old they are. To do this, they use something called a "stellar isochrone". This is just a fancy way of saying they look at a graph that shows how bright and how big each star is.

The scientists compare their observations of the stars to this graph, and they can figure out the age of the stars based on how they fit onto the graph. It's kind of like a big puzzle - they have to find the right spot on the graph for each star, and when they do that, they can figure out how old the whole group is.

So basically, a "stellar isochrone" is just a tool that helps scientists figure out how old a group of stars is, by comparing the brightness and size of different stars to a graph. Pretty neat, huh?