Describe the following adjectives : Heliocentric homocentric and concentric. [MEG 101 Prerestoration]

These adjectives are used to describe the arrangement of objects in space, particularly in relation to one another. Here are their definitions:

Heliocentric: This term describes a model of the solar system in which the Sun is located at the center, with the planets and other celestial bodies orbiting around it. The word "heliocentric" comes from the Greek words "helios" meaning "sun" and "kentron" meaning "center". This model was first proposed by the ancient Greek astronomer Aristarchus and later refined by the Polish astronomer Nicolaus Copernicus in the 16th century.

Homocentric: This term refers to objects that share the same center, or have the same axis of rotation. In astronomy, this can refer to a group of celestial bodies that are moving in the same direction and at the same speed, such as a cluster of stars. The word "homocentric" comes from the Greek words "homoios" meaning "similar" and "kentron" meaning "center".

Concentric: This term describes objects that share the same center but have different radii. In other words, the objects are arranged in a series of circles or spheres that share a common center point. In astronomy, this can refer to the arrangement of planets or other celestial bodies that are arranged in concentric orbits around a central object, such as the Sun. The word "concentric" comes from the Latin words "con-" meaning "together" and "centrum" meaning "center".