The dusty material being added to a protostar is known as a(n)
A) dark nebula.
B) emission nebula.
C) planetary nebula.
D) circumstellar accretion disk.

Question

Quizplus · Accepted Answer

The dusty material being added to a protostar is known as a circumstellar accretion disk. Dark nebulae are clouds of dust and gas in space that obscure the light of background stars or extend out from the central star in an emission nebula. Planetary nebulae are formed during the final stages of a Sun-like star's life, when a star has exhausted the fuel in its core and swollen into a red giant, and then sheds its outer layers, leaving behind a white dwarf.

The Dusty Material Being Added to a Protostar Is Known