Discovery and Characterization of sub-Neptune Exoplanets
|Date||3 December 2019|
The discovery and characterization of Hot Jupiters -- gas giant planets on few-day orbits -- was the subject of the latest Nobel Prize, and has been a fecund area of research since these planets were discovered a quarter-century ago. However, these planets are intrinsically rare: much more common are planets roughly the size of Neptune and smaller, the so-called sub-Neptunes and super-Earths. These smaller worlds represent the typical end product of the star and planet formation process, yet to date few have been subjected to detailed scrutiny beyond their bulk properties (mass, radius, and density). I will describe the large numbers of new sub-Neptunes discovered in recent years by space-based transit photometry, and discuss some of our emerging insights into their atmospheric structure and composition.