Transit depth

Definition

Transit depth measures the decrease in a star's brightness as a planet passes in front of it. It is used to determine the size of the exoplanet relative to its host star.

5 Must Know Facts For Your Next Test

1. Transit depth is directly related to the size ratio between the exoplanet and its host star.
2. A deeper transit indicates a larger planet or a closer proximity to the star during transit.
3. Transit depth helps astronomers estimate an exoplanet's radius when combined with other observations.
4. It is typically expressed as a percentage or fraction representing how much light is blocked by the planet.
5. The Kepler Space Telescope has used transit depth measurements extensively to discover thousands of exoplanets.

Review Questions

• How does transit depth help in determining the size of an exoplanet?
• What does a deeper transit indicate about an exoplanet?
• In what units is transit depth usually expressed?

Related terms

Exoplanet: A planet that orbits a star outside our solar system.

Light Curve: A graph showing how the brightness of an astronomical object changes over time.

Kepler Space Telescope: A space observatory launched by NASA to discover Earth-like planets orbiting other stars.