Description: An exoplanet, or extrasolar planet, is a planet located outside the Solar System. Their existence was theorized from the 16th century and observational research was started in the 19th century to find them. The first confirmed exoplanets were discovered in the 1990s. Of these, the first confirmed to be orbiting around a star on the main sequence was the exoplanet Dimidium, indirectly discovered at the Haute-Provence Observatory. This exoplanet is orbiting the star 51 Pegasi, a yellow subgiant and was discovered in 1995. Since then thousands of exoplanets have been identified.

Related Terms:

• Planet
• Star

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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