Stars Are Formed from Interstellar Matter

question 105

Multiple Choice

Stars are formed from interstellar matter. Why then are stars in open clusters metal-rich, while stars in globular clusters are metal-poor?

• A) Open clusters contain very hot stars that produce metals by nuclear reactions in their outer layers.
• B) Globular clusters have "burned" their heavy elements over their longer lifetime.
• C) Globular clusters are too young for their stars to have produced any significant amount of metals.
• D) Open clusters are young, and stars have formed from material that has been enriched in metals by supernova explosions of previous stars.