相关论文: Tidal Inflation Reconciles Low-Density Sub-Saturns…
The internal thermal and magnetic evolution of rocky exoplanets is critical to their habitability. We focus on the thermal-orbital evolution of Earth-mass planets around low mass M stars whose radiative habitable zone overlaps with the…
Interior to the gaseous envelopes of Saturn, Uranus, and Neptune, there are high-density cores with masses larger than 10 Earth masses. According to the conventional sequential accretion hypothesis, such massive cores are needed for the…
Much attention has been given to the climate dynamics and habitable boundaries of synchronously rotating planets around low mass stars. However, other rotational states are possible, particularly when higher eccentricity orbits can be…
Tidal torques can alter the spins of tidally interacting stars and planets, usually over shorter timescales than the tidal damping of orbital separations or eccentricities. Simple tidal models predict that, in eccentric binary or planetary…
Recent analyses have revealed a mystery. The orbital period of the highly inflated hot Jupiter, WASP-12b, is decreasing rapidly. The rate of inspiral, however, is too fast to be explained by either eccentricity tides or equilibrium stellar…
Some recently discovered short-period Earth to Neptune sized exoplanets (super Earths) have low observed mean densities which can only be explained by voluminous gaseous atmospheres. Here, we study the conditions allowing the accretion and…
The efficiency of tidal dissipation provides a zeroth-order link to a planet's physical properties. For super-Earth and sub-Neptune planets in the range $R_{\oplus}\lesssim R_p \lesssim 4 R_{\oplus}$, particularly efficient dissipation…
The newfound ability to detect SO2 in exoplanet atmospheres presents an opportunity to measure sulfur abundances and so directly test between competing modes of planet formation. In contrast to carbon and oxygen, whose dominant molecules…
Recent discoveries of water-rich, sub-Neptunian to Neptunian-massed exoplanets with short-period orbits present a new parameter space for the study of exoplanetary dynamos. We explore the geometry of the dynamo source region within this…
Super-puffs are a class of low-mass, large-radius planets that have challenged planet formation and evolution models. Their high inferred H/He mass fractions, required to explain their physical sizes, would lead to rapid atmospheric escape,…
The field of extrasolar planets has rapidly expanded to include the detection of planets with masses smaller than that of Uranus. Many of these are expected to have little or no hydrogen and helium gas and we might find Earth analogs among…
Though missions such as Kepler, K2, and TESS have discovered $>$2,000 sub-Neptune and Neptunian planets, there is a dearth of such planets at close-in (P$\lesssim$3 days) orbits. This feature, called the Neptune desert or the evaporation…
Layered semi-convection could operate in giant planets, potentially explaining the constraints on the heavy elements distribution in Jupiter deduced recently from Juno observations, and contributing to Saturn's luminosity excess or the…
The hot Saturn population exhibits a boundary in mass-radius space, such that no planets are observed at a density less than $\sim$0.1 g cm$^{-3}$. Yet, planet interior structure models can readily construct such objects as the natural…
The demographics of sub-Jovian planets around low-mass stars is dominated by populations of ``sub-Neptunes" and ``super-Earths", distinguished by the presence or absence of envelopes of low-molecular weight volatiles, i.e., H2, He, and H2O.…
Recent {\em Kepler} observations revealed an unexpected abundance of "hot" Earth-size to Neptune-size planets in the inner $0.02-0.2$ AU from their parent stars. We propose that these smaller planets are the remnants of massive giant…
We use the clathrate hydrate trapping theory to calculate the enrichments in O, N, S, Xe, Ar and Kr compared to solar in Saturn's atmosphere. For this, we calibrate our calculations using two different carbon abundance determinations that…
(Abridged) Inspired by the Kepler planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that…
The recent advancements in exoplanet observations enable the potential detection of exo-Venuses, rocky planets with carbon-rich atmospheres. How extended these atmospheres can be, given high carbon abundances, has not been studied. To…
We perform numerical simulations of the TRAPPIST-1 system of seven exoplanets orbiting a nearby M dwarf, starting with a previously suggested stable configuration. The long-term stability of this configuration is confirmed, but the motion…