Astronomy quiz question: start of type II supernova

Astronomy 210 Quiz 5, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

A type II supernova will begin when:
(A) hydrogen is transferred to a companion white dwarf.
(B) strong stellar winds are generated.
(C) too much radioactivity is produced.
(D) nuclear reactions remove energy from the core.

Correct answer: (D)

A star will use energy production in its core (which expands the star) in order to counterbalance gravity (which contracts the star). At the end of its supergiant stage, a massive star will have converted its core into iron, and further nuclear fusion will begin to take energy in rather than releasing it. As a result, the core will collapse, and the implosion-explosion process of a type II supernova will begin.

Response (A) refers to a nova (or a type Ia supernova).

Section 30674
Exam code: quiz05n4rA
(A) : 23 students
(B) : 1 student
(C) : 3 students
(D) : 11 students

"Success level": 53% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.68