超新星遗迹─延髓星云
2021年01月18日 The Medulla Nebula Supernova Remnant Image Credit & Copyright: Russell Croman Explanation: What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could...