Hypothetical astronomical objects

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.

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.

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