Heliocentric

Over a 20 year period of time, Tycho Brahe made consistent observations which supported the heliocentric theory proposed earlier by Copernicus. These observations were made using only a compass and a sextant.

Copernicus felt that Ptolemy's theory was incorrect. Sometime between 1507 and 1515, he first circulated the principles of his heliocentric or Sun-centered astronomy.

In 1632, he published a book that stated, among other things, that the heliocentric theory of Copernicus was correct. Galileo was once again called before the Inquisition and this time was found guilty of heresy.

The heliocentric view of the world, in which the Sun is at the centre of the universe, is also described as the Copernican system. It represents a step forward from the geocentric view of Ptolemy.

a heliocentric coordinate system

a heliocentric orbit

To make the Catalogue of Eclipses, as also the Table of the Parallaxes of [Jupiter], it was necessary first to make a Table of [Jupiter]' Heliocentrick places, to which the Parallaxes being applied, give the Geocentrick.

Apollyon, who, as god of the sun, has a certain stake in the matter, teaches the Prior the truth of what the Greeks, Pythagoras' disciples, knew many years before— the nature of the heliocentric (or pyrocentric) planetary system.