File:Transit Method of Detecting Extrasolar Planets.jpg

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Summary

Description	English: 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.
Date	8 September 2012, 02:51:35
Source	http://www.nasa.gov/mission_pages/kepler/multimedia/images/kepler-transit-graph.html
Author	NASA

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