A M-type main sequence star, also referred to as a red dwarf is the smallest and coolest kind of star on the main sequence. Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighborhood of Sol, but because of their low luminosity, individual red dwarfs cannot be easily observed.
Stellar models indicate that red dwarfs less than 0.35 M☉ are fully convective. Hence, the helium produced by the thermonuclear fusion of hydrogen is constantly remixed throughout the star, avoiding helium buildup at the core, thereby prolonging the period of fusion. Low-mass red dwarfs therefore develop very slowly, maintaining a constant luminosity and spectral type for trillions of years, until their fuel is depleted. Because of the comparatively short age of the universe, no red dwarfs yet exist at advanced stages of evolution.
| Horus (star) |
| Orion (star) |
See also
- M-type main-sequence star on Wikipedia