A star that has swollen in size towards the end of its life, having converted all the hydrogen in its core to helium. Such stars lie above the main sequence of the Hertzsprung–Russell diagram. A giant is brighter, larger, and cooler than a main-sequence star of the same mass. Giants have diameters 5–40 or more times that of the Sun, and luminosities from tens to thousands of times the Sun’s. They are of luminosity class II or III. See also blue giant; red giant.