The sub-Jovian desert of exoplanets: parameter dependent boundaries and implications on planet formation

Abstract: The period-mass and period-radius distribution of exoplanets is known to exhibit a desert. Unlike the existence of very hot ($P_{\rm orb}<3$d) super-Earths and hot Jupiters, no planets are known between a super Earths and sub-Jupiters with as short orbital periods as a day or two. In this Letter, we show that the period boundary of this desert is dependent on stellar parameters ($T_{\rm eff}$, $[M/H]$, $\log g$ in the order of significance), there is a conclusive dependence on the incident stellar irradiation, and a dependence on the stellar mass acting only on planets around $T_{\rm eff}<5600$K host stars. We found a significant lack of very inflated planets on closest orbits to the host star. There is no significant dependence on tidal forces currently acting on the planet, planet's surface gravity, or current filling factor of Roche lobe. These distributions are most compatible with the dominant role of photoevaporation in forming the desert.