Accretion disc

Explanation

An accretion disc is a disc of gasses and particles that are formed in a nebula when the cloud collapses towards the center under the influence of mutual gravitation. To conserve angular momentum, the denser region spins faster and draws in the rest of the particles around it either spirally or in an orbit around it. This is known as the accretion disc. The phenomenon in which the mass accumulates at the center is called as accretion.