A tidal disruption event occurs when a star is torn apart by tidal forces near a black hole, producing a luminous flare as debris accretes.

• A. It occurs when a star is captured and forms a stable binary with the black hole.
• B. It occurs when a star is directly swallowed with no flare.
• C. It occurs when a star is torn apart by tidal forces, creating a bright flare from accretion.
• D. It occurs when a black hole experiences rapid spin changes.

Answer: (C)

A tidal disruption event happens when a star ventures close enough to a black hole that the black hole’s tidal gravity overwhelms the star’s self-gravity, shredding the star apart. The shredded debris then forms an accretion flow around the black hole; as this material spirals in and heats up, it releases a bright flare. That flare is the observable signature of the event, powered by the energy released as the debris accretes.

So this choice captures the essential sequence: tidal tearing by the black hole, followed by accretion-powered bright emission. The other descriptions don’t fit: forming a stable binary with the black hole isn’t what a tidal disruption entails, a star swallowed whole with no flare would not produce the characteristic accretion-driven luminosity, and rapid spin changes of the black hole aren’t the mechanism behind a tidal disruption event.