9  Summary of Week 5

This week you have learned why transiting exoplanets are so important. Transiting planets are the only exoplanets with measured radii, which allows you to work out a lot more about them than you could otherwise. You have been introduced to the hot Jupiter HD 209458 b and learned about its key properties. You’ve also seen how efficiently you can find exoplanets using the transit method. Searching for transits from space with a purpose-built satellite called Kepler has resulted in discoveries of more than 2600 transiting exoplanets.

You should now be able to:

• know HD 209458 b was the first transiting exoplanet
• be able to explain how astronomers measure an exoplanet’s size and mass
• appreciate the importance of transiting exoplanets
• be able to describe the numbers of exoplanets discovered by the transit and radial velocity methods
• know that close-in exoplanets are more likely to transit.

Next week you’ll learn more about the findings from Kepler and what they mean for our understanding of planets in our Galaxy and the possibilities for extraterrestrial life.

You can now go to Week 6.