恩克和蝌蚪
(原标题: Encke and the Tadpoles)
2023-10-27
浏览次数: 16
历史上第二颗已知的周期彗星是恩克彗星（2P/Encke）。当它在太阳系内部旋转时，恩克的轨道将它从木星轨道内的远日点（离太阳最远的地方）带到水星轨道内的近日点。恩克彗星每3.3年返回一次近日点，是太阳系主要彗星中周期最短的彗星。恩克彗星还与地球上（至少）每年两次的流星雨有关，即北金牛座和南金牛座。这两个流星雨都在10月下旬和11月初活跃。它们两个独立的辐射点位于金牛座明亮的毕宿五附近。恩克彗星是一颗暗淡的彗星，在这张8月24日早晨的望远镜视野中被捕捉到。然后，恩克漂亮的绿色彗发靠近天空中嵌入的年轻星团和发射星云IC 410中长达数光年的蝌蚪状恒星形成云。现在，位于室女座的明亮恒星斯比卡附近的恩克彗星在5天前，也就是10月22日刚刚经过了2023年的近日点。
查看原文解释
History's second known periodic comet is Comet Encke (2P/Encke). As it swings through the inner Solar System, Encke's orbit takes it from an aphelion, its greatest distance from the Sun, inside the orbit of Jupiter to a perihelion just inside the orbit of Mercury. Returning to its perihelion every 3.3 years, Encke has the shortest period of the Solar System's major comets. Comet Encke is also associated with (at least) two annual meteor showers on planet Earth, the North and South Taurids. Both showers are active in late October and early November. Their two separate radiants lie near bright star Aldebaran in the head-strong constellation Taurus. A faint comet, Encke was captured in this telescopic field of view imaged on the morning of August 24. Then, Encke's pretty greenish coma was close on the sky to the young, embedded star cluster and light-years long, tadpole-shaped star-forming clouds in emission nebula IC 410. Now near bright star Spica in Virgo Comet Encke passed its 2023 perihelion only five days ago, on October 22.
© Dan Bartlett