Stars with low temperatures.

Hydrogen-burning red stars are small and use their available fuel slowly. These low-mass stars last for tens to hundreds of billions of years — much longer than hotter-burning stars. Some red stars are very bright, which means they are also very large. These giants, or supergiants, are stars nearing the ends of their lives. Betelgeuse (beta Orionis) is an example of a red supergiant star.