Astronomers Believe That Disks of Material Will Form Around Protostars

Multiple Choice

Astronomers believe that disks of material will form around protostars that are spinning. Which of the following observed phenomena is a good indication of the presence of a disk around a protostar?

A) HII regions
B) huge pillars of dust, like those seen by the Hubble in the Eagle Nebula
C) jets and Herbig-Haro objects
D) the presence of molecules in giant clouds of gas and dust
E) gamma rays detected from the direction of giant molecular clouds
Section 21.2: The H-R Diagram and the Study of Stellar Evolution