A Star Is Observed to Be on or Close to the Main-Sequence

question 113

Multiple Choice

A star is observed to be on or close to the main-sequence region of the Hertzsprung-Russell diagram. What particular feature of stellar behavior can be inferred by this observation?

• A) The star is generating internal energy by hydrogen fusion.
• B) The star is generating energy by helium fusion, having stopped hydrogen "burning."
• C) The star is slowly shrinking and thereby releasing gravitational potential energy as it slides down the main sequence from top left to bottom right across the H-R diagram.
• D) Stars that have reached the main sequence have ceased nuclear "burning" and are simply cooling down by emitting radiation.

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Definitions:

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Cognitive processes that involve analysis, synthesis, and evaluation, requiring more advanced intellectual skills and judgement.

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A prominent Russian psychologist known for his theory on social development and the concept of the Zone of Proximal Development, emphasizing the role of social interaction in cognitive development.