NGC 7331 and Beyond
影像版權與提供: R. Jay GaBany
Explanation:
Spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, deep telescopic exposures often result in an image that evokes a strong sense of depth. The effect is further enhanced in this well-framed view by the galaxies that lie beyond this beautiful island universe. The background galaxies are about one tenth the apparent size of NGC 7331 and so lie roughly ten times farther away.
說明:
螺旋星系NGC 7331常被說成是我們銀河系的翻版。 NGC 7331位在北天的飛馬座 (Pegasus)內，距離我們有五千萬光年遠，它在很久之前就被分類為螺旋星系，而且是十八世紀梅西葉編著名的星表時，沒有收錄的較明亮星系之一。因為在我們視線方向這個星系是傾斜的，望遠鏡深空影常能呈現鮮明的層次感。在這幅精選的星野影像裡，這個美麗的宇宙島在後方星系的襯托之下，層次感更加強烈。背景星系的視覺大小約是 NGC 7331的十分之一，因此它們的距離大約也是十倍遠。
資料來源: Scientific American
Department of Physics, NCKU
