2025年12月11日
Galaxies in the River
Image Credit & Copyright: Vikas Chander
Explanation: Large galaxies grow by eating small ones. Even our own galaxy engages in a sort of galactic cannibalism, absorbing small galaxies that are too close and are captured by the Milky Way’s gravity. In fact, the practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation Eridanus, The River. Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531, a struggle the smaller galaxy will eventually lose. Seen nearly edge-on, in this sharp image spiral NGC 1532 spans about 100,000 light-years. The NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion known as M51.
Tomorrow’s picture: fox fires
河中的星系
影像提供与版权: Vikas Chander
说明: 大型星系会透过吞噬小型星系而不断成长。甚至我们自己的银河系也参与了某种形式的星系同类相食过程，吸收那些过于接近并被银河系重力捕获的小型星系。事实上，这种现象在宇宙中相当普遍，而位于南天的河流星座波江座岸边这对引人注目的相互作用星系便是最好的例证。位于超过5000万光年外的巨大的螺旋星系NGC 1532正与矮星系NGC 1531展开重力上的角力，最终矮星系NGC 1531将败下阵来。在这张清晰的影像中，我们几乎是从侧面观察的螺旋星系NGC 1532，它的跨度约为10万光年。NGC 1532/1531 这对星系与研究较为深入的正面螺旋星系及其小型伴星系系统M51很类似。
明日的图片: fox fires
