The Comparison of Five Methods of Detecting Exoplanets

Abstract

Detecting exoplanets has become a hot topic, where various detection scenarios have been proposed. Five of these methods have all found more than 50 exoplanets, which are the transit method, the radial velocity method, the microlensing method, the imaging method, and the timing method. This paper aims to find their pros and cons, and the type of exoplanet that is suitable for each method by comparing the characteristics of exoplanets found by each method and the detection result of each method. The transit method is suitable for exoplanets with short periods possessing the advantages of measuring various parameters of exoplanets simultaneously, but can confuse exoplanets and other celestial bodies with the same radius of planets. The radial velocity method is best for exoplanets with small orbit radius or large mass, whereas it can only determine the minimum mass of exoplanets. The microlensing method can find exoplanets that are extremely far from the Earth or even rogue planets, as well as their mass. However, it does not allow researchers to observe the exoplanets found by it twice. The imaging method offers a tool to directly observe exoplanets in the infrared band. It can detect exoplanets that are extremely far from their host star with relatively high temperatures or rogue planets, but these are also the types of exoplanets that it can be detected. The timing method allows observers to discover exoplanets around pulsars, pulsating stars, eclipsing binaries, and planetary systems with discovered planets, but it is limited to these types.