exoplanetár

Exoplanetár, or exoplanetar in certain languages, refers to a planet that orbits a star other than the Sun. The standard English term is exoplanet; exoplanetar is the localized form used to describe such planets in some linguistic contexts.

Discovery methods for exoplanetár rely on indirect techniques. The transit method detects slight dips in starlight when a planet passes in front of its star; radial-velocity measurements observe the star’s Doppler wobble caused by the planet’s gravity. Other methods include direct imaging, gravitational microlensing, and astrometry. Since the 1990s, thousands of exoplanetar have been confirmed, with many discovered by transit surveys such as Kepler and TESS.

Exoplanetar span a wide range of sizes and orbits—from rocky super-Earths to gas giants larger than Jupiter; some orbit very close to their stars (hot Jupiters), while others lie in temperate zones or far from their stars. Multi-planet systems are common, and orbital configurations vary from near-resonant to highly eccentric.

Atmospheres can be studied for some exoplanetar through transmission spectroscopy during transits, revealing signatures such as water vapor, methane, or carbon dioxide. Habitability depends on multiple factors, including the host star’s radiation, planetary mass and composition, atmospheric properties, magnetic field, and whether liquid water could persist on the surface.

The study of exoplanetar informs models of planet formation and evolution, disk dynamics, and the diversity of planetary systems. Ongoing and future missions and telescopes aim to characterize atmospheres and search for potentially habitable worlds.