Statistical Research on Characteristics of Exoplanets

Abstract

In this article, main parameters of exoplanets and their host stars, including mass, orbital period, semi-major axis, density, etc., are used to analyze their physical properties. When the planet density is plot versus the semi-major axis for all available exoplanets, it is found that no obvious correlation could be observed. We then concentrate on multi-object planetary systems, which contain at least five planets. It is found that in some systems, there is an obvious positive correlation between the planet density and the semi-major axis, while others show no correlation or even a negative correlation between them. These two kinds of planetary systems seem to have different formation route. Especially, the latter group of planetary systems may have experienced some perturbations. Our study offers a closer look at the connections between exoplanets main parameters and their formation history.