Agent Exoplanet

Have you ever wondered how astronomers discover planets orbiting stars outside our solar system? This activity takes you through the steps astronomers use when they study extrasolar planet transits.

Interactive exoplanet data

Agent Exoplanet is an interactive web project which lets you measure the brightness of a star with a transiting planet. As the planet goes between us and the star, the planet blocks some of the light from the star. We measure this dip in brightness and see a light curve. Properties of this light curve give us information about the planet's size, mass, orbital distance and orbital speed.

Start analyzing exoplanet data!

Classroom resources

Are you a teacher? Do you want to use Agent Exoplanet in your classroom lessons? These resources are designed to help you to integrate this project into your class.

Teacher's guideview
Student worksheetview

Further reading

If you would like to know more about how stars evolve, please check out our SpaceBook pages about exrasolar planet transits.

Activity time: 
30 minutes or less

State that during a transit, a planet goes between us and a star and blocks some of the light we receive from the star.

Describe the shape of a light curve for a star with a transiting planet.

  • Use Agent Exoplanet to measure the brightness of a star during a planet transit and to plot a light curve of the transit.
  • Use Agent Exoplanet to calculate the mass, orbital period, orbital radius, and radius of an extrasolar planet.