👉 The term "archidium" is a term used in astronomy to describe an object that is both a planet and a star. It was first described by the Greek astronomer Ptolemy in the 3rd century AD, and it has been used in various forms throughout history. In contemporary use, "archidium" refers to any celestial body that is both a planet and a star, including asteroids, comets, and other objects. It can be difficult to define with precision