red dwarf(redirected from M dwarf)
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Related to M dwarf: red dwarf star
red dwarfAny of a large group of main-sequence stars, mainly M and K stars, that are much cooler, smaller, and less massive than the Sun (about 0.1–0.7 MO ). The convective motion within these stars, in combination with their rotation, generates a magnetic field, and the stars display a range of magnetically initiated phenomena similar to and sometimes more energetic than those occurring on the Sun. These include starspots, flares, and hot chromospheres and coronae. See also flare stars; dwarf star.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006