完美的螺旋星系M74
M74: The Perfect Spiral
也許它還不夠完美，不過至少這個螺旋星系是屬於最上相者之一。 這個正面對著我們的壯麗M74，是一個位在雙魚座內的宇宙島，距離我們有三千二百萬光年遠，擁有大約一千億顆成員星。被歸類為Sc星系的M74，它巨大且優雅的漩渦臂上面鑲著明亮的藍色星團和黝黑的宇宙塵埃帶。 這張極清晰的影像是從哈伯太空望遠鏡的先進巡天相機，在2003年和2005年所拍攝的影像組合出來的。影像涵蓋了星系M74表面約三萬光年的區域，部份影像之曝光在於捕捉了氫原子所發出的幅射，因此突顯了星系內會發出紅色輝光的大型恆星形成區。
If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view. Classified as an Sc galaxy, the grand design of M74’s graceful spiral arms are traced by bright blue star clusters and dark cosmic dust lanes. Constructed from image data recorded in 2003 and 2005, this sharp composite is from the Hubble Space Telescope’s Advanced Camera for Surveys. Spanning about 30,000 light-years across the face of M74, it includes exposures recording emission from hydrogen atoms, highlighting the reddish glow of the galaxy’s large star-forming regions.
