The red hypergiant VY CMa is bigger than Betelgeuse and belching out vast clouds of dust

When it comes to star sizes, there are dwarfs, there are giants, and there are supergiants.

And then there are hypergiants.

These are very massive stars that live fast, die young, and go out with an enormous bang: Supernovae. And now we know that before they go they also suffer from coughing fits: epic eruptions of clouds of dust that scream away at high speed, causing the star to change rapidly and profoundly in brightness.

If that sounds familiar, yeah, keep Betelgeuse in mind. We'll get ba...