Earth-sized planet found in habitable zone.

• Position: Astrophysics - Kepler-186f - Brief article

An Earth-like planet orbiting the habitable zone of a cool star has been detected by University of Notre Dame (Ind.) astrophysicist Justin R. Crepp and researchers from NASA. The planet, which was found using the Kepler Space Telescope, has been identified as Kepler-186f and is 1.11 times the radius of the Earth. Kepler-186f is part of a multiplanet system around the star Kepler 186, which has five planets, one of which is in the center of the habitable zone --the region around a star within which a planet can sustain liquid water on its surface.

While there have been other discoveries of Earth-sized and smaller planets, those planets have been found in orbits that are too close to their host stars for water to exist in liquid form. Findings taken from three years of data show that the intensity and spectrum of radiation from Kepler-186f indicate that the planet could have an Earth-like atmosphere and water at its surface that is likely to be in liquid form.

"The host star, Kepler 186, is an M1-type dwarf star, which means it will burn hydrogen...