Planet Occurrence: Doppler and Transit Surveys

TL;DR

This paper reviews how Doppler and transit surveys have advanced our understanding of planet occurrence around Sun-like stars, especially for short-period and Earth-sized planets, over the past decade.

Contribution

It provides an overview of recent survey results and the improved methods used to detect and analyze exoplanets around Sun-like stars.

Findings

Detection of a diverse population of planets around Sun-like stars.

Increased precision of Doppler spectrographs enables detection of Earth-sized planets.

Space telescopes have significantly expanded knowledge of short-period planets.

Abstract

Prior to the 1990s, speculations about the occurrence of planets around other stars were based only on planet formation theory, observations of circumstellar disks, and the knowledge that at least one seemingly ordinary star had managed to make a variety of different planets. Since then, Doppler and transit surveys have revealed the population of planets around other Sun-like stars, especially those with orbital periods shorter than a few years. Over the last decade these surveys have risen to new heights with Doppler spectrographs capable of 1 m/s precision, and space telescopes capable of detecting the transits of Earth-sized planets. This article is a brief introductory review of the knowledge of planet occurrence that has been gained from these surveys.