Using the cumulative catalog of planets detected by the NASA Kepler mission , we reconstruct the intrinsic occurrence of Earth- to Neptune-size ( 1 – 4 R _ { \oplus } ) planets and their distributions with radius and orbital period .
We analyze 76,711 solar-type ( 0.8 < R _ { * } / R _ { \odot } < 1.2 ) stars with 430 planets on 20–200 d orbits , excluding close-in planets that may have been affected by the proximity to the host star .
Our analysis considers errors in planet radii and includes an “ iterative simulation ” technique that does not bin the data .
We find a radius distribution that peaks at 2–2.8 Earth radii , with lower numbers of smaller and larger planets .
These planets are uniformly distributed with logarithmic period , and the mean number of such planets per star is 0.46 \pm 0.03 .
The occurrence is \sim 0.66 if planets interior to 20 d are included .
We estimate the occurrence of Earth-size planets in the “ habitable zone ” ( defined as 1–2 R _ { \oplus } , 0.99–1.7 AU for solar-like stars ) as 6.4 ^ { +3.4 } _ { -1.1 } \% .
Our results largely agree with those of ( ) , although we find a higher occurrence of 2.8–4 Earth-radii planets .
The reasons for this excess are the inclusion of errors in planet radius , updated ( ) stellar parameters , and also the exclusion of planets which may have been affected by proximity to the host star .