- You may also be looking for a red supergiant.
A red giant is a very large, relatively cool star, formed when a main sequence star runs out of hydrogen and begins fusing helium. Some red giants were considered B class stars. (TNG: "We'll Always Have Paris")
An unstable red giant could eventually go supernova, a process that took centuries. The odds of finding such a star in any given sector were high. (DIS: "Such Sweet Sorrow")
Azati Prime, the location where the Xindi built their weapon in the 2150s, was a red giant star, one of seven spread over about forty light years. (ENT: "Stratagem", "Azati Prime")
The central star in the Bopak system was a red giant. (DS9: "Hippocratic Oath")
The Vandor system was a binary star system that was comprised of a red giant and a pulsar. It was chosen by Paul Manheim as the site of his temporal experiments because of the system's unique gravity signature. (TNG: "We'll Always Have Paris")
A binary star system in the Kavis Alpha sector, studied by Doctor Paul Stubbs with his egg probe in early 2366, consisted of a neutron star and a red giant. (TNG: "Evolution")
The Nyrian system contained a red giant star. (VOY: "Displaced")
One of the Think Tank's accomplishments was re-igniting the red giants of the Zai Cluster. (VOY: "Think Tank")
The Kaelon sun, previously a yellow dwarf, was in the process of transforming into a red giant by 2367. It was expected to destroy its inhabited planet Kaelon II around the 2390s. (TNG: "Half a Life")
In 2377, a red giant was one of the obstacles during the Antarian Trans-stellar Rally. Tom Paris and B'Elanna Torres had to adjust the Delta Flyer's course when approaching it and recalibrated their sensors to compensate for photonic interference. (VOY: "Drive")
Soon after, a trio of Ferengi hatched an elaborate plan to steal Seven of Nine's nanoprobes by using two red giants to create a geodesic fold. (VOY: "Inside Man")
In 2378, Seven of Nine noted that USS Voyager's sensors had detected a red giant in a region of space supposedly under the control of the R'Kaal. (VOY: "Renaissance Man")
In 2383, Dal R'El unintentionally guided the USS Protostar to a binary system consisting of a red giant in the final stages of being torn apart by its white dwarf companion. The ship became caught in the white dwarf's gravity well, but managed to escape by riding the shockwave of the star's explosion. (PRO: "Starstruck")
In 2401, red giant was listed as one of the results in Raffaela Musiker's search for the "red lady". (PIC: "The Next Generation")