When observing a star that increases dramatically in brightness, if a plateau is observed inthe light curve during the declining phase, the event is probably:
A)a nova.
B)a Type I supernova.
C)a Type II supernova.
D)fusion in an accretion disk around a white dwarf.
E)fusion in an accretion disk around a neutron star.

Question

Quizplus · Accepted Answer

A plateau in the light curve during the declining phase is characteristic of a Type II supernova. This plateau occurs because of the recombination of hydrogen in the ejecta, which releases energy over a longer period.

When Observing a Star That Increases Dramatically in Brightness, If