超新星遗迹——延髓星云
2023年4月24日 The Medulla Nebula Supernova Remnant Image Credit & Copyright: Kimberly Sibbald 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 ...