Can you find the exoplanet?

In this activity you will learn how to reveal the presence of a planet orbiting a star other than the Sun using the “transit method”. You will use an open source software to observe a time series of images of the sky taken by the Spitzer Space Infrared Telescope, and to measure the change in light intensity of three different stars over time. You will then observe which one has a variation over a short period and understand that this decrease corresponds to the transit of a planet along the star’s line of sight. Using a simplified model of the planet/star system, you will also be able to determine the planet’s radius from your observations.