NGC 2440英文原文

    NGC 2440是另一个行星状星云,但它较NGC 2346有更加复杂的结构。NGC 2440的中央星是已知最热的恒星之一,表面温度大约200,000摄氏度。其周围星云的复杂结构暗示天文学家那儿存在源自中央星的周期性的喷射,有点类似NGC 2346。但是对于NGC 2440,每次喷射的方向是不确定。同时,星云中充满着尘埃云,它们形成了从中央星向外辐射的暗而长的条纹。另外,对于其中明亮的星云,是由于受中央星辐射的紫外线激发所至。NGC 2440被一个大而冷的星云所包围,它在一般的望远镜中是不可见,但在红外望远镜中却可以被探测到。NGC 2440坐落在距地球4,000光年的船尾座内。




   译自 哈勃网站(

NGC 2440
Chinese Version

  NGC 2440 is another planetary nebula ejected by a dying star, but it has a much more chaotic structure than NGC 2346. The central star of NGC 2440 is one of the hottest known, with a surface temperature near 200,000 degrees Celsius. The complex structure of the surrounding nebula suggests to some astronomers that there have been periodic oppositely directed outflows from the central star, somewhat similar to that in NGC 2346, but in the case of NGC 2440 these outflows have been episodic, and in different directions during each episode. The nebula is also rich in clouds of dust, some of which form long, dark streaks pointing away from the central star. In addition to the bright nebula, which glows because of fluorescence due to ultraviolet radiation from the hot star, NGC 2440 is surrounded by a much larger cloud of cooler gas which is invisible in ordinary light but can be detected with infrared telescopes. NGC 2440 lies about 4,000 light-years from Earth in the direction of the constellation Puppis.

  The Hubble Heritage team made this image from observations of NGC 2440 acquired by Howard Bond (STScI) and Robin Ciardullo (Penn State). 


   From Hubble Web(