The Life of a Star
4 marks · NormalThe diagram below represents simplified stages in the life of a star with a mass much greater than our Sun.
Describe what happens to the star as it moves from red supergiant (C) to supernova (D).
Explain the main difference between the neutron star and black hole outcomes (E, F).
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(a) The red supergiant becomes unstable and explodes as a supernova, throwing most of its mass into space.
(b) A neutron star forms if the leftover core is less than about five times the mass of the Sun; if more, it collapses further to form a black hole from which not even light can escape.
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Marking points
M1 (a) · 1 mark · Mention that the red supergiant becomes unstable.
A1 (a) · 1 mark · Explains that the star explodes as a supernova, casting mass into space.
B1 (b) · 1 mark · Correctly states a neutron star forms if the remnant core is less massive.
B2 (b) · 1 mark · Explains a black hole forms if the core is massive enough to collapse completely.
Worked solution
a) After the red supergiant phase, the star becomes unstable and explodes as a supernova, ejecting its outer layers.
b) If the remaining core is less than about five solar masses, it becomes a neutron star; if more, it collapses further into a black hole from which light cannot escape.