Helium fusion enhancement was a concept in which a dying star could be revitalized.
In 2367, the USS Enterprise-D conducted a test on Beta Praxillus using specially-modified photon torpedoes, designed by Kaelon scientist Timicin. Due to the similarities of Beta Praxillus and the Kaelon sun, the test was designed to determine if the same process could be performed on the dying Kaelon sun, thereby saving the Kaelon. The photon torpedoes successfully reached Praxillus's stellar core, and at first it appeared that the experiment was successful. The star's temperature continued to increase, however, and the star nova. (TNG: "Half a Life")