20thcentury astronomicalinstruments astronomicalobservatories astrophysics ccdcameras congresses focalplanes galaxies gammarayastronomy herschelspaceobservatory(spacecraft) history infraredspectroscopy infraredtelescopes instruments jameswebbspacetelescope(spacecraft) millimeterastronomy nuclearastrophysics particles(nuclearphysics) populations spaceastronomy spacetelescopes spectra spiralgalaxies spitzerspacetelescope(spacecraft) stars telescopes textbooks unitedstates x-rayastronomy