You Discover a Binary Star System in Which One Member

question 121

Multiple Choice

You discover a binary star system in which one member is a15 solar mass main-sequence star and the other star is a 10 solar mass giant star. How do we believe that a star system such as this might have come to exist?

• A) The giant must once have been the more massive star but transferred some of its mass to its companion.
• B) Other than the very low odds of finding a system with two such massive stars, there is nothing surprising about the fact that such systems exist.
• C) The two stars probably were once separate but became a binary when a close encounter allowed their mutual gravity to pull them together.
• D) The main-sequence star probably is a pulsating variable star and therefore appears to be less massive than it really is.
• E) Although both stars probably formed from the same clump of gas, the more massive one must have had its birth slowed so that it became a main-sequence star millions of years later than its less massive companion.

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Definitions:

Zone of Calcification

A region in bone where cartilage is being replaced by bone tissue during the growth process.

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Air-filled cavities in the bones around the nose, which help moisten and filter inhaled air.

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