In the Beginning – The First Exoplanet Discoveries

Abstract

Detecting exoplanets is very difficult, which is why success has only been achieved within the last couple of decades or so. An exoplanet is small, of low mass and very faint compared with its host star and it is right next door to that host star. So if you try to look for the exoplanet directly, its light will be swamped by that emitted by the star. If you try to detect the star changing its position in the sky as the exoplanet moves around it, then that movement will be buried in the uncertainties in your measurements of the star’s position. Likewise, if you try to detect the star’s changing velocity as the exoplanet orbits its host star, then those changes will also be buried in the uncertainties in your measurements of the star’s spectrum.