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In our solar system, the presence of rings is exclusive to the gas giants, but is this the case for all planetary systems? In principle, it seems that rocky exoplanets could also have rings, which could be searched for by studying their subtle imprint on the ingress and egress of transits. Unfortunately, such effects are difficult to measure and require high precision photometric and/or spectroscopic observations. At the most basic level though, the presence of rings would result in an increased transit depth that could be mistaken as an anonymously large radius. Motivated by this, I consider how a population of exoplanets with rings would impact radius measurements, focusing on Earth-like exoplanets. It is found that this population introduces an enhancement of inferred radii in the range of $sim2-3R_oplus$, not unlike the sub-Neptunes that have been identified in recent transit surveys. Whether rings can explain all or most sub-Neptunes seems difficult, since it would require a large fraction of rocky planets to have rings ($gtrsim40%$) and/or a factor of $sim2-3$ increase in the number of planets with radii $lesssim1.2R_oplus$. Even if rings cannot explain all sub-Neptunes, this work suggests that focusing on those planets currently classified as sub-Neptunes may be a good starting place for finding rocky planets with rings.
Data suggest that most rocky exoplanets with orbital period $p$ $<$ 100 d (hot rocky exoplanets) formed as gas-rich sub-Neptunes that subsequently lost most of their envelopes, but whether these rocky exoplanets still have atmospheres is unknown. We
Mass and radius of planets transiting their host stars are provided by radial velocity and photometric observations. Structural models of solid exoplanet interiors are then constructed by using equations of state for the radial density distribution,
To ascertain whether magnetic dynamos operate in rocky exoplanets more massive or hotter than the Earth, we developed a parametric model of a differentiated rocky planet and its thermal evolution. Our model reproduces the established properties of Ea
Planets with 2 $R_{oplus}$ < $R$ < 3 $R_{oplus}$ and orbital period $<$100 d are abundant; these sub-Neptune exoplanets are not well understood. For example, $Kepler$ sub-Neptunes are likely to have deep magma oceans in contact with their atmospheres
An intriguing, growing class of planets are the super-puffs, objects with exceptionally large radii for their masses and thus correspondingly low densities ($lesssim0.3rm,g,cm^{-3}$). Here we consider whether they could have large inferred radii beca