Oldest Planetary Nebula Hosted by 500-Million-Old Galactic Cluster Discovered: All Details

The oldest visible planetary nebula has been discovered by astronomers inside a 500-million-year-old galactic open cluster. These planetary nebulas are glowing shrouds ejected from dying stars, which present a spectacular sight. Believed to be of high astrophysical value, the rare celestial jewel has been discovered inside a cluster called M37 and is said to have a ki...