Free Astronomy Magazine July-August 2014

29 EXOPLANETS JULY-AUGUST 2014 The growing zoo of ex- trasolar planets never ceases to amaze, as fur- ther confirmed by the re- cent discovery of an object that does not be- long to any class of plan- ets already known, since although not much larg- er than our Earth it is 17 times heavier. It could well be the first example of a large population of mega-Earths. lso s A t the last meeting of the American Astronomical Society held this June in Boston, some important novelties concerning extrasolar planets were officially announced, both with reference to some theoretical aspects related to their forma- tion, and as regards to their detection and discovery. One of the most interesting topics was presented by the team led by Lars Buchhave (Harvard-Smithsonian Center for Astrophysics, University of Copenhagen), which analyzes the relationship between the various types of planets and the metal- licity of the star around which they orbit.