The Outer Edge of the Venus Zone around Main-sequence Stars

Abstract A key item of interest for planetary scientists and astronomers is the habitable zone: distance from a host star where terrestrial planet can maintain necessary temperatures in order to retain liquid water on its surface. However, when observing system’s zone, it possible that one may instead observe Venus-like planet. We define “Venus-like” as greenhouse-gas-dominated atmosphere occurring incoming solar radiation exceeds infrared emitted at top atmosphere, resulting runaway greenhouse. Our definition includes both incipient post-runaway greenhouse states. Both possibility world Venus could represent an end state evolution worlds require improved understanding planet, specifically distances these planets exist. Understanding this helps us “Venus zone”—the region which exist—and assess overlap with aforementioned “habitable zone.” In study, we use 1D radiative−convective climate model determine outer edge zone F0V, G2V, K5V, M3V M5V stellar spectral types. results show resides 3.01, 1.36, 0.68, 0.23, 0.1 au, respectively. These correspond incident fluxes 0.8, 0.55, 0.38, 0.32, 0.3 S ⊙ , respectively, flux relative Earth (1.0). indicate there be considerable between zone.