A Class K star is the second-dimmest type of main sequence star besides brown dwarfs. They are typically colored yellow-orange or orange. They make up roughly 12% of all main-sequence stars.

A typical Class K star has a mass of 0.6 (0.45 to 0.8) solar masses, a radius of 0.8 (0.7 to 0.96) solar radii, a luminosity of 0.3 (0.08 to 0.6) solar luminosities, a surface temperature of 4,450 K (3,700 K to 5,200 K), and a lifespan of 50 to 100 billion years.

With their extremely long lifespans and acceptable brightness, it is very likely that many Class K stars have life-bearing planets, and many exoplanets have been discovered around stars of this class.

Stellar Classes
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