Arp 142：蜂鸟星系

Arp 142：蜂鸟星系

Arp 142: The Hummingbird Galaxy
Image Credit: NASA, ESA, Hubble, HLA; Processing & Copyright: Basudeb Chakrabarti

Explanation: What’s happening to this spiral galaxy? Just a few hundred million years ago, NGC 2936, the upper of the two large galaxies shown at the bottom, was likely a normal spiral galaxy — spinning, creating stars — and minding its own business. But then it got too close to the massive elliptical galaxy NGC 2937, just below, and took a turn. Sometimes dubbed the Hummingbird Galaxy for its iconic shape, NGC 2936 is not only being deflected but also being distorted by the close gravitational interaction. Behind filaments of dark interstellar dust, bright blue stars form the nose of the hummingbird, while the center of the spiral appears as an eye. Alternatively, the galaxy pair, together known as Arp 142, look to some like Porpoise or a penguin protecting an egg. The featured re-processed image showing Arp 142 in great detail was taken recently by the Hubble Space Telescope. Arp 142 lies about 300 million light years away toward the constellation of the Water Snake (Hydra). In a billion years or so the two galaxies will likely merge into one larger galaxy.

Tomorrow’s picture: big blue horse

Arp 142：蜂鸟星系
影像提供: NASA, ESA, Hubble, HLA; 影像处理与版权: Basudeb Chakrabarti

说明: 这个螺旋星系发生了什么事？近在数亿年前，影像中这二个大星系位在上方的NGC 2936，很可能还是一个正常的螺旋星系，自顾自的旋转、创造恒星、忙自己的事。后来，它太靠近下方的庞大椭圆星系NGC 2937，于是情况就急转直下。因其标志性的外观而有蜂鸟星系之称的NGC 2936，在近距离引力交互作用的扰动下，不但方向发生了偏移，外观也出现了扭曲。在黝黑星际尘埃细丝的后方，可见到由明亮泛蓝恒星所构成的鸟喙，而螺旋的中心则像一只眼睛。此外，合称为Arp 142的这对星系，在某些人的眼里形似鼠海豚或在抱蛋的企鹅。这幅经过重处理的极细致主题影像，是哈勃太空望远镜最近所拍摄的影像之一。Arp 142位于长蛇座方向约3亿光年远之处。大约在10亿年之内，这2个星系可能会合并成一个更大的星系。 （Hummingbird Galaxy 蜂鸟星系；Porpoise Galaxy 鼠海豚星系）

明日的图片: big blue horse