Discovery and Validation of Kepler-452b: A 1.6 R Super Earth Exoplanet in the Habitable Zone of a G2 Star

August 2015 • 2015AJ....150...56J

Authors • Jenkins, Jon M. • Twicken, Joseph D. • Batalha, Natalie M. • Caldwell, Douglas A. • Cochran, William D. • Endl, Michael • Latham, David W. • Esquerdo, Gilbert A. • Seader, Shawn • Bieryla, Allyson • Petigura, Erik • Ciardi, David R. • Marcy, Geoffrey W. • Isaacson, Howard • Huber, Daniel • Rowe, Jason F. • Torres, Guillermo • Bryson, Stephen T. • Buchhave, Lars • Ramirez, Ivan • Wolfgang, Angie • Li, Jie • Campbell, Jennifer R. • Tenenbaum, Peter • Sanderfer, Dwight • Henze, Christopher E. • Catanzarite, Joseph H. • Gilliland, Ronald L. • Borucki, William J.

Abstract • We report on the discovery and validation of Kepler-452b, a transiting planet identified by a search through the 4 years of data collected by NASA’s Kepler Mission. This possibly rocky {1.63}-0.20+0.23 {R}\oplus planet orbits its G2 host star every {384.843}-0.012+0.007 days, the longest orbital period for a small ({R}{{P}}< 2 {R}\oplus ) transiting exoplanet to date. The likelihood that this planet has a rocky composition lies between 49% and 62%. The star has an effective temperature of 5757 ± 85 K and a {log}g of 4.32 ± 0.09. At a mean orbital separation of {1.046}-0.015+0.019 AU, this small planet is well within the optimistic habitable zone of its star (recent Venus/early Mars), experiencing only 10% more flux than Earth receives from the Sun today, and slightly outside the conservative habitable zone (runaway greenhouse/maximum greenhouse). The star is slightly larger and older than the Sun, with a present radius of {1.11}-0.09+0.15 {R} and an estimated age of ∼6 Gyr. Thus, Kepler-452b has likely always been in the habitable zone and should remain there for another ∼3 Gyr.


IPAC Authors


David Ciardi

Senior Scientist