Related papers: Evidence of Different Formation Mechanisms for Hot…
We investigate a population of transiting planets that receive relatively modest stellar insolation, indicating equilibrium temperatures $< 1000$ K, and for which the heating mechanism that inflates hot Jupiters does not appear to be…
Planets and stars are expected to be compositionally linked because they accrete from the same material reservoir. However, astronomical observations revealed the existence of exoplanets whose bulk density is far higher than what is…
Planets in the mass range from 2 to 15 MEarth are very diverse. Some of them have low densities, while others are very dense. By measuring the masses and radii, the mean densities, structure, and composition of the planets are constrained.…
We present the discovery of a super-earth-sized planet in or near the habitable zone of a sun-like star. The host is Kepler-69, a 13.7 mag G4V-type star. We detect two periodic sets of transit signals in the three-year flux time series of…
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…
Ultra-short-period (USP) planets are a newly recognized class of planets with periods shorter than one day and radii smaller than about 2 Earth radii. It has been proposed that USP planets are the solid cores of hot Jupiters that lost their…
We have numerically studied the thermal evolution of various-mass terrestrial planets in habitable zones, focusing on duration of dynamo activity to generate their intrinsic magnetic fields, which may be one of key factors in habitability…
To date, two planetary systems have been discovered with close-in, terrestrial-mass planets (< 5-10 Earth masses). Many more such discoveries are anticipated in the coming years with radial velocity and transit searches. Here we investigate…
Exoplanets with lower equilibrium temperatures than Earth and primordial hydrogen atmospheres that evaporate after formation should pass through transient periods where oceans can form on their surfaces, as liquid water can form below a few…
While giant extrasolar planets have been studied for more than two decades now, there are still some open questions such as their dominant formation and migration process, as well as their atmospheric evolution in different stellar…
Recent studies suggest that ultra-short period planets (USPs), Earth-sized planets with sub-day periods, constitute a statistically distinct sub-sample of {\it Kepler} planets: USPs have smaller radii ($1-1.4R_\oplus$) and larger mutual…
Ultra-short period (USP) planets are an enigmatic subset of exoplanets defined by having orbital periods $<$ 1 day. It is still not understood how USP planets form, or to what degree they differ from planets with longer orbital periods.…
Context. The discovery of about 700 extrasolar planets, so far, has lead to the first statistics concerning extrasolar planets. The presence of giant planets seems to depend on stellar metallicity and mass. For example, they are more…
We present a statistical study of the planet-metallicity (P-M) correlation, by comparing the 744 stars with candidate planets (SWPs) in the Kepler field which have been observed with LAMOST, and a sample of distance-independent, fake "twin"…
A rapidly growing body of observational results suggests that planet formation takes place preferentially at high metallicity. In the core accretion model of planet formation this is expected because heavy elements are needed to form the…
We develop a pebble-driven model to study the formation and evolution of planets around stars in the mass range of 0.08 and 1 solar mass. The growth and migration of a large number of individual protoplanetary embryos are simulated in a…
We explore whether close-in super-Earths were formed as rocky bodies that failed to grow fast enough to become the cores of gas giants before the natal protostellar disk dispersed. We model the failed cores' inward orbital migration in the…
NASA's Kepler mission has discovered thousands of planetary systems, ~20% of which are found to host multiple transiting planets. This relative paucity (compared to the high fraction of single transiting systems) is postulated to result…
Exoplanets around different types of stars provide a window into the diverse environments in which planets form. This chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to…
Super-Earths, a class of planetary bodies with masses ranging from a few Earth-masses to slightly smaller than Uranus, have recently found a special place in the exoplanetary science. Being slightly larger than a typical terrestrial planet,…