First Earth-size exoplanet in the habitable zone of its star

[Ivy Matt]

Kepler-186f is the first Earth-size planet found in the habitable zone of its star. The announcement from NASA is here.

Distance: 492 light years
Star type: M1 red dwarf
Star mass: 0.48 solar masses
Habitable zone: 0.21-0.44 AU
Orbital distance: 0.356 AU
Orbital period: 129.9 (Earth) days
Radius: 1.11 Earth radii

The mass, density, and composition of the planet are unknown. The radiation flux it receives from its star is 32% of the radiation flux Earth receives from the Sun. There are five confirmed planets in the Kepler-186 system. All are roughly Earth-size. The other four planets are too close to the star to be in the habitable zone.

[vansig]

we should note that previous planets were larger, mostly because it’s harder to detect small planets. it is also harder to detect planets in orbits that are like the earth’s.. (periods around one earth year) than those with shorter periods.

[Author]

Posts