NGC 4631:鲸鱼星系



NGC 4631: The Whale Galaxy
Image Credit & Copyright:
Michael Sherick

Explanation: NGC 4631 is a big beautiful spiral galaxy. Seen edge-on, it lies only 25 million light-years away in the well-trained northern constellation Canes Venatici. The galaxy’s slightly distorted wedge shape suggests to some a cosmic herring and to others its popular moniker, The Whale Galaxy. Either way, it is similar in size to our own Milky Way. In this sharp color image, the galaxy’s yellowish core, dark dust clouds, bright blue star clusters, and red star forming regions are easy to spot. A companion galaxy, the small elliptical NGC 4627 is just above the Whale Galaxy. Faint star streams seen in deep images are the remnants of small companion galaxies disrupted by repeated encounters with the Whale in the distant past. The Whale Galaxy is also known to have spouted a halo of hot gas glowing in X-rays.

Tomorrow’s picture: jovian close-up

NGC 4631:鲸鱼星系
Michael Sherick

说明: NGC 4631是一个美丽庞大的螺旋星系。这个位于猎犬座方向的侧向星系,距离我们只有2,500万光年远。此星系稍微变形的楔形外观,对有些人来说形似一条宇宙级的鲱鱼,其他人则认为它应称为鲸鱼星系。不论如何,鲸鱼星系是个大小与我们银河系相近的天体。在这幅清晰的彩色影像里,此星系泛黄的核心、黝黑的尘埃云、泛蓝的的星团与泛红的恒星形成区皆轻易可辨。此外,在鲸鱼星系上方,还可见到它椭圆形的小伴星系NGC 4627。在这幅影像里,还可见到在遥远的过去,其他小型伴星系重复接近鲸鱼星系后,被扯碎所留下的暗淡恒星流遗迹。鲸鱼星系还拥有一团会辐射出X射线的炽热气晕。

明日的图片: jovian close-up