Astronomia nova

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Title page.

Astronomia nova aitiologetos: sev physica coelestis, tradita commentariis de motibvs stellæ Martis, ex observationibus G. V. Tychonis Brahe, jussu & sumptibus Rvdolphi II ... plurimum annorum pertinaci studio elaborata Pragæ ... Heidelberg: G. Voegelinus, 1609.

Kepler's Astronomia Nova presents two of Kepler's laws. The first is that planets move in ellipses, not circles or epicycles, and that the sun is one of the foci. The second law is that the line between the sun and a planet sweeps equal spaces in equal times.

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Page 131 - diagaram.