When massive stars come to the end of their life cycles, they self-destruct in a cataclysmic final explosion.
Rosette Nebulae are red, O-type stars are blue...
The galaxy cluster, featured in a Hubble Space Telescope photo, weighs in at three million billion suns.
"Growing black holes behave like babies that become too energetic and throw their food off the table once they eat enough."
Dark matter could make up around 80 percent of the mass in the universe.
The weird clouds could come from another galaxy.
The galaxies had been invisible to every other instrument that ever looked at them.