SN 1999em

SN 1999em is a well-studied supernova that occurred in the galaxy NGC 1637, about 40 million light-years away. It was classified as a Type II-P supernova, formed when a massive star exhausted its nuclear fuel and its core collapsed, resulting in a huge explosion. This explosion ejected outer layers into space, creating a bright, expanding glow observable from Earth. SN 1999em has helped astronomers understand stellar evolution and the mechanics of supernova explosions, serving as a valuable example of how massive stars end their lives in spectacular displays of energy.