Methods of Exoplanet Detection

The Transit Method

The transit method hinges on tiny dips in light from a star caused as a planet crosses its face. Despite only being viable for planets that pass between their star and observers, it’s delivered over 3,700 exoplanet discoveries.

Gravitational Microlensing

Responsible for the detection of about 130 planets, lensing occurs when objects of tremendous mass warp the fabric of space. By observing the curvature of light from a distant object, details can be ascertained about intervening objects, like planets.

The Radial Velocity Method

A technique based on the fact that a planet and a star orbit a point of mutual mass, meaning the presence of a planet can be seen as a ‘wobble’ in the star’s motion. Also known as the wobble method, this has delivered around 900 discoveries.

Direct Imaging

Occasionally, by blocking the light from a parent star astronomers can actually directly image an exoplanet. This method has resulted in the discovery of 54 worlds outside the Solar System. This includes TYC 8998-760-1 b and c, pictured below.