In Star Trek: The Next Generation, what technology lets the Enterprise-D create an artificial sun for a damaged planet?

In Star Trek: The Next Generation, a focused graviton beam lets the Enterprise-D create an artificial sun for a damaged planet.

The technology appears in “Parallels,” where the Enterprise encounters a reality in which Worf is returning from a Klingon bat’leth tournament. The episode’s central problem involves a planet whose sun has been destroyed. The Enterprise uses its advanced gravitational technology to help provide an artificial stellar source.

A graviton is a hypothetical particle associated with gravity in some theoretical physics models. Star Trek uses graviton-based devices imaginatively, including systems that manipulate gravitational forces. The Enterprise’s beam is therefore a fictional application of a concept borrowed from theoretical science.

This answer should not be confused with a phaser beam, tractor beam, or stellar-reconstruction device from another Star Trek story. The key detail is the focused graviton beam’s role in producing an artificial sun in “Parallels.”