Related papers: Where can we find Super-Earths?
Many exoplanets have been discovered with radii of 1-4 Earth radii, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are "sub-Neptunes" likely to have…
There is growing evidence that the population of close-in planets discovered by the Kepler mission was sculpted by atmospheric loss, though the typical timescale for this evolution is not well-constrained. Among a highly complete sample of…
In most extrasolar planetary systems, the present orbits of known giant planets admit the existence of stable terrestrial planets. Those same giant planets, however, have typically eccentric orbits that hint at violent early dynamics less…
Exoplanet observations show that close-in super-Earths are more common around M-dwarfs than around solar mass stars. Since the snow line in a protoplanetary disc plays a crucial role in determining the amount of solid material available for…
We report relations between inner ($<1$ au) super Earths (planets with mass/radius between Earth and Neptune) and outer ($>1$ au) giant planets (mass $>0.3~M_{\rm J}$, or cold Jupiters) around Sun-like stars, based on data from both…
Visible and near-infrared spectra of transiting hot Jupiter planets have recently been observed, revealing some of the atmospheric constituents of their atmospheres. In the near future, it is probable that primary and secondary eclipse…
A recently discovered group of nearby co-orbital objects is an attractive location for extraterrestrial intelligence (ETI) to locate a probe to observe Earth while not being easily seen. These near-Earth objects provide an ideal way to…
A handful of stars are known to host both an inner system of multiple transiting planets and an outer giant planet. These systems all feature a prominent gap between the orbits of two of the transiting planets, distinguishing them from…
Although current sensitivity limits are such that true Solar System analogs remain challenging to detect, numerous planetary systems have been discovered that are very different from our own Solar System. The majority of systems harbor a…
Two decades ago, astronomers began detecting planets orbiting stars other than our Sun, so-called exoplanets. Since that time, the rate of detections and the sensitivity to ever-smaller planets has improved dramatically with several…
Recent observations found close-in planets with significant atmospheres of hydrogen and helium in great abundance. These are the so-called super-Earths and mini-Neptunes. Their atmospheric composition suggests that they formed early during…
Jupiter-mass planets with large semi-major axes ($a > 1.0$ AU) occur at a higher rate around evolved intermediate mass stars. There is a pronounced paucity of close-in ($a < 0.6$ AU), intermediate period ($5 < P < 100$ days), low-mass…
Kepler's observations show most of the exoplanets are super-Earths. The formation of super-Earth is generally related to the atmospheric mass loss that is crucial in the planetary structure and evolution. The shock driven by the giant…
Motivated by recent measurements of the free-floating planet mass function at terrestrial masses, we consider the possibility that the solar system may have captured a terrestrial planet early in its history. We show that $\sim 1.2$…
The widespread prevalence of close-in, nearly coplanar super-Earth- and sub-Neptune-sized planets in multiple-planet systems was one of the most surprising results from the Kepler mission. By studying a uniform sample of Kepler "multis"…
Since planet occurrence and primordial atmospheric retention probability increase with period, the occurrence-weighted median planets discovered by transit surveys may bear little resemblance to the low-occurrence, short-period planets…
Doppler and transit surveys are finding extrasolar planets of ever smaller mass and radius, and are now sampling the domain of superEarths (1-3 Earth radii). Recent results from the Doppler surveys suggest that discovery of a transiting…
The majority of gas giants (planets of masses $\gtrsim10^2 M_\oplus$) are found to reside at distances beyond $\sim1$ au from their host stars. Within 1 au, the planetary population is dominated by super-Earths of $2-20 M_\oplus$. We show…
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…
Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in…