How would you expect a star that formed recently in the disk of the galaxy to differ from one that formed early in the history of the disk?
A) It should have a higher fraction of elements heavier than hydrogen and helium.
B) It should be higher in mass.
C) It should be much brighter.
D) It should orbit the galactic center at a much higher rate of speed.
E) All of the above would be expected.

Question

Quizplus · Accepted Answer

Stars that form later in the history of the galaxy have had more time for heavier elements to be produced and mixed into the interstellar gas, which can then be incorporated into the stars that form from this gas. Thus, we would expect a star that formed recently in the disk of the galaxy to have a higher fraction of elements heavier than hydrogen and helium compared to a star that formed early in the history of the disk.

B, C, and D are not necessarily true for all stars that formed recently in the disk of the galaxy, as the mass, brightness, and speed of a star depend on multiple factors, such as its initial mass, age, and location in the galaxy.

How Would You Expect a Star That Formed Recently in the Disk