“河内星云”，属于银河系内太阳系外由气体和尘埃组成的云雾状天体Milky Way nebula; Milky Way nebulae(plural)

• 我们所能看到的只局限于银河系的星云，即所谓银河星云。

  We are limited in what we can see to nebulae within the Milky Way, or Milky Way nebulae.

• 我们整个银河星云和整个宇宙相比，也非常之渺小。

  All Milky Way nebulae are minuscule in comparison to the universe as a whole.