ELI5: Explain Like I'm 5

Open cluster family

Imagine an open cluster family as a group of stars that are all related and live together in the same neighborhood. Just like how you have a family at home, these stars have a family too!

But instead of living in houses like you do, these stars float around in space together. They are called an "open" cluster family because they are spread out and not tightly packed together like another type of cluster family called a "globular" cluster.

These stars in an open cluster family are all born around the same time from a big cloud of gas and dust, kind of like how siblings are born around the same time from their mom. They grow up together and stay close to each other throughout their lives.

Sometimes a few stars will break away from the family and go off on their own adventures, just like how some of your family members may move away from home. But for the most part, these stars stick together and form beautiful patterns in the sky that we call constellations.

Overall, an open cluster family is just a big group of stars that all grow up together and stay close throughout their lives, creating beautiful patterns in the sky for us to admire from Earth.