渦うず巻まき星せい雲うん

noun

spiral nebula

Obsolete astronomical term for what is now called a spiral galaxy. Used historically before the nature of galaxies was fully understood.

• 19世せい紀きの天てん文もん学がく者しゃは、アンドロメダを渦うず巻まき星せい雲うんと呼よんでいた。

  In the 19th century, astronomers called Andromeda a spiral nebula.