Outlines of Astronomy

amount angle angular appear apsides ascertained astronomical attraction axis bright calculation celestial circle coincidence comet described determined diameter difference direction disc distance disturbed body disturbing force diurnal diurnal motion double stars earth ecliptic effect elements ellipse epoch equal equator equinoctial equinox error exact excentricity fixed globe gravity heavens heliocentric horizon inclination instance interval Jupiter latitude latter length less light longitude lunar magnitude mass mean measure meridian moon moon's motion nearly nebula node normal force nutation object observed orbit parallax parallel perigee perihelion period perturbations phænomena phænomenon planet planetary pole portion position precession precisely proper motion proportion recede recess reckoned refraction remarkable render respect result revolution right ascension rotation round satellites Saturn seen sidereal sidereal day situation solar sphere spherical stars station sun's suppose syzygies tangential force telescope tion true anomaly Uranus variation velocity visible whole zenith