A History of Astronomy

accuracy afterwards altitude ancient aphelion appeared Aristotle astrology astronomical Babylonian became bright calendar Callippus catalogue celestial bodies celestial sphere centre century circle comet computed constellations Copernicus course derived determined developed deviations diameter direction disc discoveries distance doctrine earth eccentricity eclipses entirely epicycle equinox error exact explained force full moon Galileo gravity Greek heliacal rising hence Hipparchus Huygens increasing instruments irregularities Jupiter Kepler king knowledge later latitude lines longitude lunar lunar eclipses magnitude Mars means measured Mercury meridian method month moon's motion nearly nebulae Newton node object observations Observatory opposition orbit parallax parsecs phenomena planetary planets pole position practical problem proper motions Ptolemy Ptolemy's published radius refraction Regiomontanus revolution right ascension rise rotation Saturn sexagesimals showed Sirius smaller solar spherical stellar sun's synodic period tables telescope theoretical theory tion Tycho Tycho Brahe velocity Venus visible