Stellar engines are a class of hypothetical megastructures which use the resources of a star to generate available work (or, in other words, to generate energy). For instance, they can use the energy of the star to produce mechanical, electrical or chemical work or they can use the impulse of the light emitted by the star to produce thrust, able to control the motion of a star system.[1] The concept has been introduced by Bădescu and Cathcart.[2] The variants which produce thrust may accelerate a star and anything orbiting it in a given direction.[3][4] The creation of such a system would make its builders a type-II civilization on the Kardashev scale.
The proposed engines have contradictions with real physics and are therefore primarily elements of science-fiction.