散さん光こう星せい雲うん

noun

diffuse nebula

Astronomical term for a nebula that appears spread out and lacks a well-defined shape, as opposed to a planetary nebula or supernova remnant.

• 散さん光こう星せい雲うんは、星ほしの光ひかりを反はん射しゃして輝かがやいている。

  Diffuse nebulae shine by reflecting starlight.