Tutorial: Detecting Planetary Transits and Radial-Velocity Signals

Abstract

Since the discovery of the first exoplanet orbiting a main-sequence star in 1995, more than 3500 planets have been discovered. Most of these were detected and characterized by means of radial-velocity and/or photometric observations. In this tutorial we present examples of exoplanet detection and characterization using these two methods. We start by showing an application of the Box-fitting Least Squares (bls) algorithm to search for a transiting planet signal in the photometric light curve of EPIC 211089792 recorded by K2. Once the transits are detected we then show how to fit a model to the transit light curve and derive the transit parameters using a least-squares minimization algorithm. In a second exercise we show how to detect the same planet based on radial-velocity data and using the Lomb–Scargle periodogram. Finally, we exemplify how to combine the radial velocities and transits of the exoplanet EPIC 211089792b using a Bayesian approach to derive the planetary parameters. This tutorial hence covers some of the state-of-the-art methods of exoplanet search and characterization.