What is a protoplanetary disk?
A) a disk of gas and dust, such as those observed around some stars in the Orion nebula
B) a disk of debris around a planet of greater mass than Jupiter, material from which rings and moons will form
C) a disk of debris orbiting an exoplanet, for example, the planet orbiting the star 51 Pegasi
D) a disk of cold debris orbiting far from a star, such as the Oort cloud of our solar system

Question

Quizplus · Accepted Answer

A protoplanetary disk is a disk of gas and dust surrounding a newly formed star or a young star that is about to form. This disk is considered to be the birthplace of planets and other celestial bodies as the dust particles within the disk clump together to form larger objects, such as planetesimals, which eventually become planets.

What Is a Protoplanetary Disk