Question

consider a close binary system composed of a white dwarf, a giant star, and an accretion disk. which of the statements are true of this binary system, and which are false? true false answer bank the accretion disk deposits hydrogen onto the surface of the white dwarf. the white dwarf could explode as a planetary nebula. the mass of the white dwarf increases over time. the giant star can brighten as a nova due to accretion onto its surface.

Explanation:

• In a close - binary system with a white dwarf, giant star, and accretion disk, the accretion disk forms from material transferred from the giant star to the white dwarf. This material is mainly hydrogen which gets deposited onto the white - dwarf's surface, increasing its mass over time. A white dwarf can explode as a type - Ia supernova if it reaches the Chandrasekhar limit, not as a planetary nebula (a planetary nebula is formed when a low - to medium - mass star like the Sun sheds its outer layers at the end of its life). A nova occurs on the surface of a white dwarf, not a giant star, when the accreted hydrogen undergoes a thermonuclear explosion.

Answer:

True: The accretion disk deposits hydrogen onto the surface of the white dwarf, The mass of the white dwarf increases over time
False: The white dwarf could explode as a planetary nebula, The giant star can brighten as a nova due to accretion onto its surface