M Dwarf Stars are the smallest and coolest type of main-sequence stars, classified as spectral type M. They have a mass between about 0.08 and 0.6 times that of the Sun and a surface temperature ranging from 2,400 to 3,700 Kelvin. Due to their low luminosity, they are often difficult to see with the naked eye. These stars are known for their long lifespans, lasting tens of billions of years, much longer than larger stars. M Dwarfs are also of interest in the search for exoplanets because their habitable zones are closer to the star, making it easier to detect orbiting planets.