Phaä

Phaä is a hypothetical exoplanet located in the Kepler-186 system. It is the fifth and outermost known planet orbiting the star Kepler-186, a red dwarf located approximately 500 light-years away from Earth in the constellation Cygnus. Phaä's existence is inferred from data collected by the Kepler Space Telescope, which searches for exoplanets using the transit method. This method detects slight dips in a star's brightness as a planet passes in front of it.

The Kepler-186 system is notable for containing Kepler-186f, the first Earth-size planet discovered in the habitable zone of another star. Phaä is located beyond the habitable zone, meaning that if it possesses an atmosphere, surface temperatures would likely be too cold to support liquid water. Its orbital period is estimated to be around 130 days. Due to its distance from its star and the star's lower luminosity compared to our Sun, Phaä would receive significantly less stellar radiation.

Little is known about Phaä's physical characteristics, such as its mass, radius, or atmospheric composition. Current observations are insufficient to determine these details. Further study of the Kepler-186 system and the potential detection of additional transits or other observational evidence would be necessary to confirm Phaä's existence and to learn more about this distant world. The discovery of multiple planets in the Kepler-186 system highlights the diversity of planetary systems around red dwarf stars.