The Kepler mission found hundreds of planet candidates within the Habitable Zones ( HZ ) of their host star , including over 70 candidates with radii larger than 3 Earth radii ( R _ { \oplus } ) within the optimistic HZ ( OHZ ) \citep Kane16 .
These giant planets are potential hosts to large terrestrial satellites ( or exomoons ) which would also exist in the HZ .
We calculate the occurrence rates of giant planets ( R _ { p } = 3.0–25 R _ { \oplus } ) in the OHZ and find a frequency of ( 6.5 \pm 1.9 ) \% for G stars , ( 11.5 \pm 3.1 ) \% for K stars , and ( 6 \pm 6 ) \% for M stars .
We compare this with previously estimated occurrence rates of terrestrial planets in the HZ of G , K and M stars and find that if each giant planet has one large terrestrial moon then these moons are less likely to exist in the HZ than terrestrial planets .
However , if each giant planet holds more than one moon , then the occurrence rates of moons in the HZ would be comparable to that of terrestrial planets , and could potentially exceed them .
We estimate the mass of each planet candidate using the mass-radius relationship developed by \citet Chen16 .
We calculate the Hill radius of each planet to determine the area of influence of the planet in which any attached moon may reside , then calculate the estimated angular separation of the moon and planet for future imaging missions .
Finally , we estimate the radial velocity semi-amplitudes of each planet for use in follow up observations .