Monthly Archives: November 2015

DISCOVERY AND VALIDATION OF Kepler-452b

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from the Astronomical Journal
dx.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 (${R}_{{\rm{P}}}\lt 2$ ${R}_{\oplus }$) 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 $\mathrm{log}g$ 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 ${1.11}_{-0.09}^{+0.15}$ ${R}_{\odot }$ 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.