Fundamental Astronomy

absorption angular antenna apparent magnitude asteroids astronomy atmosphere atoms axis binary binary stars brightness centre cloud clusters colour components constant coordinates corresponding curve determined diameter direction disc distance distribution dust Earth eclipse electron elements elliptical emission energy equation extinction flux density function galactic galaxies gravitational H II regions helium HR diagram Hubble hydrogen infrared interstellar interstellar medium ionized Jupiter km/s layers light luminosity magnetic field magnitude main sequence mass measured Milky molecules Moon motion nebula neutron star nuclei object Observatory observed obtained optical orbit particles perihelion phase Photograph photon planet planetary Plate polarization pressure pulsar quasars r-process radiation radio radius redshift region right ascension rotation satellite sidereal solar system space spectral class spectral lines spectrum spherical spiral stellar supernova surface telescope temperature tion variables vector velocity Venus wavelengths white dwarf x-ray