1. Acknowledgments.- 2. Notes on Contribtutors.- 3. Introduction.- 4. The Reality of Peurbachs Orbs, (Barker).- 5. Continuity and change in cosmological ideas in Spain between the sixteenth and seventeenth centuries, (Navarro Brontos).- 6. Cornelius Gemma and the new star of 1572, (Tessicini).- 7. Johannes Kepler and David Fabricius: their discussion on the nova of 1604, Grandada.- 8. Kepler’s copernican campaign and the new star of1604, (Boner).- 9. From cosmos to confession: .- Kepler and the connection between astronomical and religious truth, (Rothman).- 10. Johannes phocylides holwarda and the interpretation of new stars in the dutch republic, (Vermij).- 11. Discovering mira ceti: celestial change & cosmic continuity, (Hatch).