20171115

Astronomy quiz question: stellar evolution states in star cluster

Astronomy 210 Quiz 6, fall semester 2017
Cuesta College, San Luis Obispo, CA

Medium-mass stars in a new star cluster will be in their __________ stage.
(A) protostar.
(B) red dwarf.
(C) white dwarf.
(D) supergiant.

Correct answer (highlight to unhide): (A)

All stars in a star cluster are born at the same time, but undergo stellar evolution at different rates depending on their masses. Medium-mass stars start out as protostars, then reach their main sequence stage, and subsequently become giants, planetary nebulae, and then white dwarfs. So an old star cluster would have medium-mass stars in their white dwarf stage; and a young star cluster would have medium-mass stars still in their protostar stage.

(Response (B) is a low-mass star stage; response (D) is a massive star stage.)

Section 70160
Exam code: quiz06nMuE
(A) : 18 students
(B) : 6 students
(C) : 3 students
(D) : 3 students

Success level: 61% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64

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