Planets Found by Kepler Spacecraft Likely Larger Than Thought

The artist's concept depicts Kepler-62f, a super-Earth planet in the habitable zone of a star smaller and cooler than the sun, located about 1,200 light-years from Earth in the constellation Lyra. 

CREDIT: NASA/Ames/JPL-Caltech

A large number of worlds found by NASA's Kepler alien planet-hunting space telescope are probably significantly larger than scientists previously estimated, a new study suggests.

The Kepler Space Telescope has spotted more than 2,700 potential exoplanets since its launch in 2009, and scientists using the Kitt Peak National Observatory Mayall 4-meter telescope have categorized the home stars of many of those planet candidates for the past three years.

In particular, the researchers made detailed follow-up observations of 300 of the stars Kepler found likely to be harboring exoplanets.

"One of the main findings of this initial work is that our observations indicate that most of the stars we observed are slightly larger than previously thought and one quarter of them are at least 35 percent larger," astronomer and leader of the study Mark Everett said in a statement.

"Therefore, any planets orbiting these stars must be larger and hotter as well. By implication, these new results reduce the number of candidate Earth-size planet analogues detected by Kepler."