描述：小螺旋星系ngc 7742正向快照，不只是古老的螺旋星系而是2型塞弗特星系——其动力可能由星系核心处的黑洞提供。
Caption: a face-on snapshot of the small spiral galaxy NGC 7742, not just any old spiral galaxy but a Seyfert 2 - a galaxy that is probably powered by a black hole at its core.
这个特别的星系归类于塞弗特1型星系，这是由于它拥有一个向四周大范围辐射氢元素的明亮核心，但奇怪的是，它还拥有数条狭窄的重元素发射带，例如铁元素。
This particular galaxy is described as Seyfert 1 galaxy, which typically have bright centres emitting a broad range of hydrogen emission but narrow emission lines of heavier elements such as iron.
这个特别的星系归类于塞弗特1型星系，这是由于它拥有一个向四周大范围辐射氢元素的明亮核心，但奇怪的是，它还拥有数条狭窄的重元素发射带，例如铁元素。
This particular galaxy is described as Seyfert 1 galaxy, which typically have bright centres emitting a broad range of hydrogen emission but narrow emission lines of heavier elements such as iron.
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