Kepler's Telescope

The story behind Kepler's Telescope

In order to measure the brightness changes of around 200,000 stars, the Kepler spacecraft was put into an earth-trailing orbit and pointed at a 100 square degree region of the sky near Cygnus. Finding exoplanets transiting these stars and figuring out how common they are in the Galaxy were its main objectives. The Kepler data is divided into 90-day quarters because the spacecraft had to rotate 90 degrees every 90 days to maintain the solar panels pointed at the sun. At either a 30-minute or 1-minute cadence, Kepler only downloaded the pixels surrounding a few picked stars of interest. The expedition created a flux time series for each star and looked for transiting exoplanets using these light curves.