We have collected transit times for the TRAPPIST-1 system with the Spitzer Space
Telescope over four years. We add to these ground-based, HST, and K2 transit-time …

Planets are expected to conclude their growth through a series of giant impacts: energetic,
global events that significantly alter planetary composition and evolution. Computer models …

The population of planets smaller than approximately 1.7 Earth radii (R⊕) is widely
interpreted as consisting of rocky worlds, generally referred to as super-Earths. This picture …

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 …

The Kepler mission, combined with ground-based radial velocity (RV) follow-up and
dynamical analyses of transit timing variations, has revolutionized the observational …

Transiting planet surveys like Kepler have provided a wealth of information on the
distribution of planetary radii, particularly for the new populations of super-Earth-and sub …

The size frequency distribution of exoplanet radii between 1 and 4R⊕ is bimodal with peaks
at∼ 1.4 R⊕ and∼ 2.4 R⊕, and a valley at∼ 1.8 R⊕. This radius valley separates two …

We use models of coupled thermal evolution and photo-evaporative mass loss to
understand the formation and evolution of the Kepler-36 system. We show that the large …

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses
and radii of USP exoplanets could provide constraints on their unknown formation and …

ABSTRACT NASA's Kepler Mission uses transit photometry to determine the frequency of
Earth-size planets in or near the habitable zone of Sun-like stars. The mission reached a …