Extrasolar Planets: November 2018

Every school kid knows that Earth has a magnetic field -- it's what makes compasses align north-south and lets us navigate the oceans. It also protects the atmosphere, and thus life, from the Sun's powerful wind.

The search for Earth-like planets around Sun-like stars and the evaluation of their occurrence rate is a major topic of research for the exoplanetary community.

The important role of stellar irradiation in envelope removal for planets with diameters of <2 R⊕ has been inferred both through theoretical work and the observed bimodal distribution of small planet occurrence as a function of radius.

A low-amplitude periodic signal in the radial-velocity (RV) time-series of Barnard's Star was recently attributed to a planetary companion with a minimum mass of ∼3.2 M⊕ at an orbital period of ∼233 days.

At a distance of 1.8 parsecs, Barnard's star (Gl 699) is a red dwarf with the largest apparent motion of any known stellar object.

The nearest single star to the Sun hosts an exoplanet at least 3.2 times as massive as Earth -- a so-called super-Earth.

Over the past decade, the study of exoplanets has shifted from their detection to the characterization of their atmospheres.