Okay kiddo, imagine you have a friend named Star. Star is very bright and shines in the night sky. Now, sometimes, stars can get very sick and end up exploding. When this explosion happens, we call it a supernova. It's a super loud and bright event that can be seen from very far away.
But sometimes, a star doesn't explode completely. It gets sick, starts to shine brighter than usual, and then fades away. This is called a supernova impostor. It's like when you pretend to be sick to skip school, but you're not actually sick and just want to stay home and play video games.
This impostor star is still very bright, but it doesn't cause a loud, explosive bang like a real supernova. Scientists are very interested in studying supernova impostors because they can help us understand how stars can get sick and what happens when they don't explode all the way.
So, just like when you pretend to be sick, these impostor stars are pretending to be supernovas, but they're not the real deal. However, they can still teach us a lot of important things about the universe!