Extrasolar Planet

An Extrasolar Planet is a planet that orbits a star other than The Sun (enabling astronomical observation and planetary system research).

• AKA: Exoplanet, Extrasolar World.
• Context:
  • It can typically orbit around extrasolar stellar objects including extrasolar main sequence stars, extrasolar red dwarfs, extrasolar binary star systems, and extrasolar stellar remnants.
  • It can typically be detected through extrasolar planet detection methods such as extrasolar transit photometry, extrasolar radial velocity measurements, extrasolar direct imaging, and extrasolar gravitational microlensing.
  • It can typically possess extrasolar planet atmospheres ranging from thin extrasolar atmospheres to thick extrasolar gaseous envelopes (affecting their extrasolar atmospheric composition).
  • It can typically orbit within extrasolar planetary systems containing multiple extrasolar planets and extrasolar minor body objects.
  • It can typically form through extrasolar planet formation processes involving extrasolar protoplanetary disk accretion and extrasolar planetary migration.
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  • It can often exhibit extrasolar planet orbital characteristics including extrasolar planet eccentricity, extrasolar planet inclination, and extrasolar planet resonance with other extrasolar planetary bodies.
  • It can often possess extrasolar planet internal structures influenced by their extrasolar planet mass, extrasolar planet composition, and extrasolar planet formation history.
  • It can often experience extrasolar planet climate conditions determined by extrasolar planet atmospheric dynamics and extrasolar stellar radiation.
  • It can often undergo extrasolar planet evolutionary processes throughout their extrasolar planetary lifetime.
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  • It can range from being an Extrasolar Milky-Way Planet to being an Extrasolar Non-Milky-Way Planet, depending on its galactic location.
  • It can range from being a Smaller-than-Earth Extrasolar Planet to being an Earth-sized Extrasolar Planet to being a Larger-than-Earth Extrasolar Planet, depending on its planetary radius.
  • It can range from being a Terrestrial Extrasolar Planet to being a Gaseous Extrasolar Planet, depending on its planetary composition.
  • It can range from being a Hot Extrasolar Planet to being a Temperate Extrasolar Planet to being a Cold Extrasolar Planet, depending on its stellar insolation and atmospheric properties.
  • It can range from being a Young Extrasolar Planet to being an Ancient Extrasolar Planet, depending on its formation age.
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  • It can serve as extrasolar planet research target for astronomical observation programs and space telescope missions.
  • It can provide extrasolar planet habitability insights through comparative planetology study.
  • It can contribute to extrasolar planet demographic analysis in stellar population surveys.
  • It can advance extrasolar planet formation theory through observational constraint.
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• Examples:
  • Extrasolar Planet Detection Method Categories, such as:
    • Transit-Detected Extrasolar Planets, such as:
      • TRAPPIST-1 Extrasolar Planet System demonstrating extrasolar multiple planet transit around an extrasolar ultracool dwarf star.
      • Kepler-186f Extrasolar Planet exhibiting extrasolar earth-sized transit signal in an extrasolar habitable zone.
    • Radial Velocity-Detected Extrasolar Planets, such as:
      • 51 Pegasi b Extrasolar Planet representing the first confirmed extrasolar planet around a sun-like extrasolar star.
      • Proxima Centauri b Extrasolar Planet showing extrasolar habitable zone positioning around the nearest extrasolar star system.
    • Direct Imaging-Detected Extrasolar Planets, such as:
      • HR 8799 Extrasolar Planet System revealing multiple directly imaged extrasolar planets around an extrasolar young star.
  • Extrasolar Planet Composition Categories, such as:
    • Gas Giant Extrasolar Planets, such as:
      • Hot Jupiter Extrasolar Planets demonstrating extrasolar planet atmospheric circulation and extrasolar planet thermal emission.
      • Cold Gas Giant Extrasolar Planets showing extrasolar planet ring systems and extensive extrasolar planet moon systems.
    • Super-Earth Extrasolar Planets, such as:
      • K2-18b Super-Earth Extrasolar Planet containing extrasolar atmospheric water vapor and carbon-bearing extrasolar molecules.
      • Gliese 581g Super-Earth Extrasolar Planet potentially supporting extrasolar planet surface liquid water.
    • Terrestrial Extrasolar Planets, such as:
      • TRAPPIST-1e Terrestrial Extrasolar Planet positioned within its star's extrasolar habitable zone.
      • LHS 1140b Terrestrial Extrasolar Planet exhibiting rocky extrasolar planet composition with potential extrasolar water content.
  • Extrasolar Planet Habitability Categories, such as:
    • Extrasolar Habitable Zone Planets, such as:
      • Extrasolar Goldi-Locks Planets demonstrating temperate extrasolar surface conditions.
      • Extrasolar Ocean Worlds potentially supporting extrasolar subsurface liquid water.
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• Counter-Examples:
  • Solar Planets, which orbit The Sun rather than another star.
  • Brown Dwarfs, which exceed the planetary mass limit and undergo limited nuclear fusion.
  • Rogue Planets, which do not orbit any star but instead travel through interstellar space.
  • Extrasolar Asteroids, which lack sufficient mass to achieve hydrostatic equilibrium.
  • Extrasolar Moons, which primarily orbit extrasolar planets rather than stars directly.
• See: Planet, Planetary System, Habitable Zone, The Extrasolar Planets Encyclopedia, Transit Method, Radial Velocity Method, Direct Imaging, Planetary Formation.

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