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 et al. 2015. "Discovery and Validation of Kepler-452b: A 1.6 R? Super Earth Exoplanet in the Habitable Zone of a." The Astronomical Journal, 150 56. https://doi.org/10.1088/0004-6256/150/2/56.
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}}\lt 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.
