nebula
n. countablen. a giant cloud of dust and gas in space. Some are formed from dying stars, while others are places where new stars are beginning to grow.
n. a diffuse cloud of interstellar dust and gas, often appearing as a luminous patch in the night sky. In modern astronomy, it refers specifically to these clouds rather than distant galaxies.
The Orion Nebula is visible through a small telescope.
Astronomers use powerful infrared cameras to peer through the thick dust of the nebula and see the stars forming inside.
The spectacular colors observed in a planetary nebula are produced by the ionization of different gases as they are heated by the intense radiation of a central white dwarf.
Borrowed from Latin nebula (“little cloud, mist”). Akin to Ancient Greek νεφέλη (nephélē, “cloud”), German Nebel (“mist, nebula”), Old Norse nifl, Polish niebo (“sky, heaven”), Russian не́бо (nébo, “sky”).
The plural form is either 'nebulae' (Latinate) or 'nebulas' (standard English).
The nebula are very brightThe nebula is very brightNebula is singular; the plural form is nebulae or nebulas.