Astronomers say they have discovered 104 exoplanets, two of which could support life.
They orbit the M type dwarf star K2-72, which is 181 light-years away.
The planets, which were discovered by using NASA’s Kepler space telescope, are 20 to 50 percent larger than Earth in diameter, astronomers said.
They are much closer to their star, which is half the size of our sun and much dimmer, than the planets of our solar system with orbits of between 5.5 and 24 days.
Two of the planets, researchers said, are exposed to irradiation levels similar to Earth's. The two planets, calledK2-72c and K2-72e, lie in an area where liquid water could exist.
K2-72c orbits its star every 15 days and is only 10 percent warmer than Earth despite its proximity to its star. On the other hand K2-72e orbits every 24 days and is likely six percent cooler than Earth.
The planets were discovered indirectly, “by measuring the subtle dip in a star's brightness caused by a planet passing in front of its star.”
The discoveries bring the total number of exoplanets discovered by Kepler to more than 2,300 since it was launched in March of 2009. That accounts for nearly two thirds of all confirmed exoplanet discoveries.
The discoveries are published online in the Astrophysical Journal Supplement Series.