M31 仙(xian)女(nv)座大星系(xi)
仙女(nv)星(xing)(xing)系(xi)(英語:Andromeda Galaxy; M31; NGC 224;曾被稱為仙女(nv)座大(da)星(xing)(xing)云),位于(yu)仙女(nv)座方位的擁有巨(ju)大(da)盤狀(zhuang)結(jie)構的旋渦(wo)星(xing)(xing)系(xi),梅西耶星(xing)(xing)表編號(hao)為M31,星(xing)(xing)云星(xing)(xing)團(tuan)新總(zong)表編號(hao)位NGC 224,直(zhi)徑22萬(wan)光年(nian),距離(li)地球有254萬(wan)光年(nian),是距銀(yin)河系(xi)最近的大(da)星(xing)(xing)系(xi)。