Extrasolar Planets: September 2017

Atmospheric tides can have a strong impact on the rotational dynamics of planets. They are of most importance for terrestrial planets located in the habitable zone of their host star, where their competition with solid tides is likely to drive the body towards non-synchronized rotation states of equilibrium, as observed in the case of Venus.

Exoplanet discoveries over recent years have shown that terrestrial planets are exceptionally common. Many of these planets are in compact systems that result in complex orbital dynamics.

The detection of Earth-like exoplanets in the habitable zone of their stars, and their spectroscopic characterization in a search for biosignatures, requires starlight suppression that exceeds the current best ground-based performance by orders of magnitude.

M-dwarfs or red dwarfs are small (0.5-0.1 solar-mass) and cool ( ~3,000 kelvin) stars and are abundant in the universe.

A new X-ray study has revealed that stars like the Sun and their less massive cousins calm down surprisingly quickly after a turbulent youth.