Circle of stars all EU leaders as the official emblem of the European Communities, and in 1993 inherited by the successor organisation, the European Union. All European institutions now use an emblem of their own. The Zodiac is an ancient "circle of stars" where some stars are symbolically combined into 12 Star signs also known as constellations. The etymology of the term Zodiac comes from the Latin zōdiacus, from the Greek ζῳδιακός [κύκλος], meaning "[circle] of animals", derived from ζῴδιον, the diminutive of ζῷον "animal". The Crown of Immortality is a separate and earlier motif (and metaphor) which also uses a circle of
Ancient Greek astronomy Perga (c. 262 BC–c. 190 BC) responded by introducing two new mechanisms that allowed a planet to vary its distance and speed: the eccentric deferent and the deferent and epicycle. The deferent is a circle carrying the planet around the Earth. (The word "deferent" comes from the Greek fero φέρω "to carry"and Latin "ferro, ferre", meaning "to carry.") An eccentric deferent is slightly off-center from Earth. In a deferent and epicycle model, the deferent carries a small circle, the epicycle, which carries the planet. The deferent-and-epicycle model can mimic the eccentric model, as shown by Apollonius' theorem. It can also