Red Dwarfs
A red dwarf is the least massive, smallest, least luminous, and coolest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, making up roughly three-quarters of all such stars, though their low brightness means they're invisible to the naked eye. Why they matter: unlike larger stars, red dwarfs burn hydrogen very slowly through a process called convection that prevents helium buildup. This allows them to shine for trillions of years, far exceeding the universe's current age. No red dwarf has ever exhausted its fuel, making them essential for understanding stellar evolution and the search for habitable planets.
Sources
- en.wikipedia.org: “A red dwarf is the least massive, smallest, least luminous, and coolest kind of star on the main sequence.”
- en.wikipedia.org: “Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the neighborhood of the Sun.”
- en.wikipedia.org: “According to some estimates, red dwarfs make up three-quarters of the fusing stars in the Milky Way.”
- en.wikipedia.org: “red dwarfs have estimated lifespans far longer than the present age of the universe”
- en.wikipedia.org: “Because of the comparatively short age of the universe, no red dwarfs yet exist at advanced stages of evolution.”