释义 |
河外星系héwài-xīngxì在银河系以外的恒星的集合体,距离地球在数百万光年以上。河外星系是和银河系相当的恒星系。{extragalactic nebula; an aggregate of fixed stars outside the Milky Way; millions of light-years from the earth; extragalactic nebula is a stellar system similar to the Milky Way;}旧称{formerly called}河外星云{héwài-xīngyún}。 |