NGC 4651:雨伞星系



NGC 4651: The Umbrella Galaxy
Image Credit & Copyright:
CFHT, Coelum, MegaCam, J.-C. Cuillandre (CFHT) & G. A. Anselmi (Coelum)

Explanation: It’s raining stars. What appears to be a giant cosmic umbrella is now known to be a tidal stream of stars stripped from a small satellite galaxy. The main galaxy, spiral galaxy NGC 4651, is about the size of our Milky Way, while its stellar parasol appears to extend some 100 thousand light-years above this galaxy’s bright disk. A small galaxy was likely torn apart by repeated encounters as it swept back and forth on eccentric orbits through NGC 4651. The remaining stars will surely fall back and become part of a combined larger galaxy over the next few million years. The featured image was captured by the Canada-France-Hawaii Telescope (CFHT) in Hawaii, USA. The Umbrella Galaxy lies about 50 million light-years distant toward the well-groomed northern constellation Coma Berenices.

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NGC 4651:雨伞星系
CFHT, Coelum, MegaCam, J.-C. Cuillandre (CFHT) & G. A. Anselmi (Coelum)

说明: 天空下的是恒星雨。如今我们知道,这个庞大形似宇宙级雨伞的天体结构,其实是从小伴星系剥离出来的潮汐恒星流。影像中心位在北天、形似秀发的后发座方向,大小和我们银河系相近,距离我们约5千万光年远,名为雨伞星系的螺旋星系NGC 4561,其伞状结构从明亮的核心向外伸展了将近10万光年的距离。随着伴星系沿着奇特的轨道来回穿梭通过NGC 4651,它终将会被拆解殆尽。而孑遗下来的恒星则会掉入NGC 4651,并在接下来的数百万年里,合并成更大的星系。这幅主题影像,是由位在美国夏威夷的加法夏望远镜(CFHT)所拍摄。


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