The Elements of Astronomy

aberration accordingly accurate actual angle subtended angular diameter angular distance angular velocity annual parallax apparent assumed astronomical calculated called celestial bodies celestial equator celestial meridian celestial sphere celestial vault centre circular measure clock collimation comet corresponding declination circle describe determined diagram direction displacement diurnal motion earth earth's orbit ecliptic elongation equal error evidently fact fixed in space follows full moon geocentric Greenwich Greenwich mean Hence horizon hour angle inclined inferior planet intersection Kepler known latitude longitude lunar disc mean noon mean sun Mercury meridian passage method moon's move nearly node obliquity parallax parallel path perpendicular phase place of observation point of Aries position precession radius refraction relative round the sun seen sidereal day sidereal period small circle solar eclipse solar system solstice spherical sun's superior planet surface Suryya Siddhanta synodic period telescope tion transit Venus vertical zenith distance Zodiac