A yellow dwarf was a classification of star which was undergoing hydrogen-helium conversion. Sol was a well-known yellow dwarf star.
In 2356, Magnus and Erin Hansen crash-landed their ship, the USS Raven, on an M-class moon orbiting the fifth planet of a yellow dwarf located in B'omar space. (VOY: "The Raven")
On stardate 49485.2 the USS Voyager visited Hemikek IV, a planet in the Hemikek yellow dwarf star system. (VOY: "Investigations")
The planet dubbed "New Earth" by the crew of the USS Voyager orbited a yellow dwarf as the third of seven planets. (VOY: "Resolutions")
Similarly, the planet Mislen was located within a yellow dwarf star system. (VOY: "The Swarm")