2026年1月19日
CTB 1: The Medulla Nebula
Image Credit: Pierre Konzelmann
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 create stabilizing pressure with nuclear fusion. The resulting supernova remnant, nicknamed the Medulla Nebula for its brain-like shape, still glows in visible light because of the heat generated by its collision with confining interstellar gas. Why the nebula also glows in X-ray light, though, remains a topic of research. One hypothesis holds that an energetic pulsar was created and powers the nebula with a fast outwardly moving wind. Following this lead, a pulsar was found in radio waves that appears to have been expelled by the supernova explosion at over 1000 kilometers per second. Although the Medulla Nebula appears as large as a full moon, it is so faint that it took 84-hours of exposure with a small telescope in Texas, USA, to create the featured image.
Tomorrow’s picture: volcano world
CTB 1: 延髓星云
影像提供: Pierre Konzelmann
说明: 是什么力量驱动着这片奇特的星云？CTB 1是大约一万年前，位于仙后座附近一颗大质量恒星爆炸后留下的不断膨胀之气体壳层。这颗恒星可能是因为核心附近的元素耗尽，无法透过核融合产生稳定的压力而爆炸。这个被昵称为延髓星云的超新星遗迹，因其形似大脑而得名，至今仍因与周围星际气体碰撞产生的热量而在可见光波段下发光。然而，这个星云为何也会在X射线波段发光，目前仍是研究的课题。一种假说认为，一颗高能量脉冲星在爆炸过程中同时形成，并以高速向外移动的星风为星云提供能量。循着这条线索，研究人员在电波波段中发现了一颗脉冲星，这颗脉冲星似乎是由超新星爆炸以每秒超过1000公里的速度所抛出的。虽然延髓星云看起来和满月一样大，但它非常暗淡，需要在美国 德州使用两台小望远镜进行了130小时的曝光，才能创建出这张特色影像。
明日的图片: volcano world
