exoplanetide

Exoplanetide is a hypothetical astronomical object, a proposed classification for a celestial body that orbits an exoplanet rather than a star. The term itself is a portmanteau of "exoplanet" and "satellite," similar to how "moon" refers to a natural satellite of a planet in our solar system. While no exoplanetides have been definitively detected to date, their existence is considered plausible given the prevalence of exoplanets.

The formation of an exoplanetide would likely mirror the formation of moons in our own solar system. This could occur through several mechanisms. Accretion disks around forming exoplanets could coalesce material to form larger bodies. Gravitational capture of rogue objects passing too close to an exoplanet is another possibility. Tidal forces from the host star could also play a role in shaping or retaining such satellites.

Detecting exoplanetides presents significant challenges. Their small size and faintness compared to their host exoplanet make direct observation extremely difficult. Indirect methods, such as observing subtle perturbations in the exoplanet's orbit or transits, might offer future avenues for discovery. The study of exoplanetides, if found, would greatly expand our understanding of planetary system formation and evolution beyond our own.