Related papers: A Rocky Composition for an Earth-sized Exoplanet
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…
Kepler-78b is one of a growing sample of planets similar, in composition and size, to the Earth. It was first detected with NASA's \emph{Kepler} spacecraft and then characterised in more detail using radial velocity follow-up observations.…
The Kepler mission has revealed that Earth-sized planets are common, and dozens have been discovered to orbit in or near their host star's habitable zone. A major focus in astronomy is to determine which of these exoplanets are likely to…
Approximately half of the extrasolar planets (exoplanets) with radii less than four Earth radii are in orbits with short periods. Despite their sheer abundance, the compositions of such planets are largely unknown. The available evidence…
Although several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long-period, low-mass exoplanets with measured masses and a corresponding lag in our understanding of such…
Terrestrial planets have been found orbiting Sun-like stars with extremely short periods --- some as short as 4 hours. These "ultra-short-period planets" or "hot Earths" are so strongly irradiated that any initial H/He atmosphere has…
The bulk chemical composition and interior structure of rocky exoplanets are of fundamental importance to understanding their long-term evolution and potential habitability. Observations of the chemical compositions of the solar system…
Stars and planets both form by accreting material from a surrounding disk. Because they grow from the same material, theory predicts that there should be a relationship between their compositions. In this study, we search for a…
The first mass-estimate of an exoplanet around a Sun-like star, 51 Peg b and the first radius measurement of an exoplanet, HD209458b pointed to the challenges of understanding the atmosphere, interior, and evolution of exoplanets including…
The quantity $\eta_\oplus$, the number density of planets per star per logarithmic planetary radius per logarithmic orbital period at one Earth radius and one year period, describes the occurrence of Earth-like extrasolar planets. Here we…
In principle, the combined measurements of the mass and radius a giant exoplanet allow one to determine the relative fraction of hydrogen and helium and of heavy elements in the planet. However, uncertainties on the underlying physics imply…
Exoplanets smaller than Neptune are common around red dwarf stars (M dwarfs), with those that transit their host star constituting the bulk of known temperate worlds amenable for atmospheric characterization. We analyze the masses and radii…
The chemical composition of stars hosting small exoplanets (with radii less than four Earth radii) appears to be more diverse than that of gas-giant hosts, which tend to be metal-rich. This implies that small, including Earth-size, planets…
Exoplanet interior modelling usually makes the assumption that the elemental abundances of a planet are identical to those of its host star. Host stellar abundances are good proxies of planetary abundances, but only for refractory elements.…
Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small…
Compared to the Earth, the exoplanet Kepler-78b has a similar size (1.2 $R_\oplus$) and an orbital period a thousand times shorter (8.5 hours). It is currently the smallest planet for which the mass, radius, and dayside brightness have all…
When an extrasolar planet passes in front of its star (transits), its radius can be measured from the decrease in starlight and its orbital period from the time between transits. Multiple planets transiting the same star reveal more: period…
About one out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultra-short-period planet (Sanchis-ojeda et al. 2014; Winn et al. 2018). All of the previously known ultra-short-period planets are either hot…
We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA's K2 Mission with follow-up Doppler measurements by the HIRES spectrometer at the W. M. Keck Observatory and the Automated Planet Finder at…
Evidence suggests the existence of a large planet in the outer Solar System, Planet Nine, with a predicted mass of 6.6 +2.6 / -1.7 Earth masses (Brown et al., 2024). Based on mass radius composition models, planet formation theory, and…