Hypothetical astronomical object
A hypothetical astronomical object is an astronomical object (such as a star, planet or moon) that is believed or speculated to exist or to have existed but whose existence has not been scientifically proven. Such objects have been hypothesized throughout recorded history. For example, in the 5th century BCE, the philosopher Philolaus "defined a hypothetical astronomical object which he called the Central Fire", around which he proposed other celestial bodies (including the Sun) moved.
Types of hypothetical astronomical objects
Hypothetical astronomical objects have been speculated to exist both inside and outside of the Solar System, and speculation has included different kinds of stars, planets, and other astronomical objects.
- For hypothetical astronomical objects in the Solar System, see List of hypothetical Solar System objects
- For hypothetical stars, see Hypothetical star
- For hypothetical brown dwarfs, see List of brown dwarfs
- For hypothetical planet types, see List of planet types
- For hypothetical planets in fiction, see Fictional planets of the Solar System
- For planets or moons whose existence is not accepted by science, see Planetary objects proposed in religion, astrology, ufology and pseudoscience
- For extrasolar moons, all of which are currently hypothetical, see Exomoon
- Marco Ceccarelli, Distinguished Figures in Mechanism and Machine Science (2007), p. 124.