相关论文: The Roche limit for close-orbiting planets: Minimu…
In this work we derive the minimum allowed orbital periods of H-rich bodies ranging in mass from Saturn's mass to 1 $M_{\odot}$, emphasizing gas giants and brown dwarfs over the range $0.0003 - 0.074 \, M_\odot$. Analytic fitting formulae…
The recent detection of planets around very low mass stars raises the question of the formation, composition and potential habitability of these objects. We use planetary system formation models to infer the properties, in particular their…
Planets with sizes between that of Earth (with radius R$_\oplus$) and Neptune (about 4 R$_\oplus$) are now known to be common around Sun-like stars. Most such planets have been discovered through the transit technique, by which the planet's…
Modeling the interior of a planet is difficult because the small number of measured parameters is insufficient to constrain the many variables involved in describing the interior structure and composition. One solution is to invoke…
Our knowledge of white dwarf planetary systems predominately arises from the region within a few Solar radii of the white dwarfs, where minor planets break up, form rings and discs, and accrete onto the star. The entry location, angle and…
By employing four typical equation of states (EOSs) of the inner crust matters, the constraint on properties of low-mass neutron stars are theoretically investigated. Based on the well known fact that there is a big gap between the neutron…
Recent analyses of Kepler space telescope data reveal that transiting planets with orbital periods shorter than about 2-3 days are generally observed around late-type stars with rotation periods longer than about 5-10 days. We investigate…
Short-period planets provide ideal laboratories for testing star-planet interaction. Planets that are smaller than $\sim$2$R_\oplus$ are considered to be largely rocky either having been stripped of or never having acquired the gaseous…
The majority of white dwarfs that host periodic transiting planetary debris do so at distances that exceed the rubble-pile Roche limit, in disagreement with canonical formation models that focus on the tidal disruption of minor planets.…
Recent studies regarding the habitability, observability, and possible orbital evolution of the indirectly detected exoplanet Proxima b have mostly assumed a planet with $M \sim 1.3$ $M_\oplus$, a rocky composition, and an Earth-like…
Detection of Jupiter mass companions to nearby solar type stars with precise radial velocity measurements is now routine, and Doppler surveys are moving towards lower velocity amplitudes. The detection of several Neptune-mass planets with…
The chemical composition of stars that have orbiting planets provides important clues about the frequency, architecture, and composition of exoplanet systems. We explore the possibility that stars from different galactic populations that…
In some recent works, the C/O abundance ratio in high-metallicity stars with planets is found to vary from 0.4 to about 1.0. This has led to discussions about the existence of terrestrial planets with a carbon-dominated composition that is…
The full range of conditions under which rocky planets can host atmospheres remains poorly understood, especially in the regime of close-in orbits around late-type stars. One way to assess the presence of atmospheres on rocky exoplanets is…
Many giant exoplanets are found near their Roche limit and in mildly eccentric orbits. In this study we examine the fate of such planets through Roche-lobe overflow as a function of the physical properties of the binary components,…
The questions of how planets form and how common Earth-like planets are can be addressed by measuring the distribution of exoplanet masses and orbital periods. We report the occurrence rate of close-in planets (with orbital periods less…
We validate the planetary nature of an ultra-short period planet orbiting the M dwarf KOI-4777. We use a combination of space-based photometry from Kepler, high-precision, near-infrared Doppler spectroscopy from the Habitable-zone Planet…
We constrain the densities of Earth- to Neptune-size planets around very cool (Te =3660-4660K) Kepler stars by comparing 1202 Keck/HIRES radial velocity measurements of 150 nearby stars to a model based on Kepler candidate planet radii and…
We study the evolution of a protoplanet of a few earth masses embedded in a protoplanetary disc. If we assume that the atmosphere of the protoplanet, i.e. the volume of gas in hydrostatic equilibrium bound to the core, has a surface radius…
We report the discovery by the CoRoT space mission of a new giant planet, CoRoT-20b. The planet has a mass of 4.24 +/- 0.23 MJ and a radius of 0.84 +/- 0.04 RJ. With a mean density of 8.87 +/- 1.10 g/cm^3, it is among the most compact…