The Transit Method of Detecting Extrasolar Planets
March 4, 2009
When a planet crosses in front of its star as viewed by an observer, the event is called a transit. Transits by terrestrial planets produce a small change in a star's brightness of about 1/10,000 (100 parts per million, ppm), lasting for 2 to 16 hours. This change must be absolutely periodic if it is caused by a planet. In addition, all transits produced by the same planet must be of the same change in brightness and last the same amount of time, thus providing a highly repeatable signal and robust detection method.
Topics: Environment, Astronomical transit, Exoplanetology, Astrometry, Doppler spectroscopy, Kepler Mission, Terrestrial planet, Extrasolar planets