Related by context. Frequent words. (Click for all words.) 77 quasars 76 galaxies 74 supermassive black hole 73 neutron star 72 galaxy clusters 72 supernovae 71 supermassive black holes 69 gamma ray burst 69 distant galaxies 69 supernova 69 pulsar 68 nebula 67 brown dwarf 66 Milky Way galaxy 66 redshift 66 brown dwarfs 66 gamma ray bursts 65 Milky Way 65 neutron stars 65 gamma rays 65 pulsars 65 galaxy 64 supernovas 64 gravitational waves 63 astronomers 63 neutrino 63 extrasolar planets 62 exoplanet 62 planets orbiting 62 exoplanets 61 cosmic rays 61 neutrinos 61 cosmic microwave background 60 comet 60 Enceladus 60 planets 60 comets 59 corona 58 photons 58 GRB 58 Saturn rings 57 gamma ray 57 fainter 57 Astronomers 57 magnetic fields 57 photon 57 infrared wavelengths 56 magnetosphere 56 Sedna 56 astrophysicists 55 spectra 55 auroras 55 sunspot 55 atoms 55 nuclei 55 solar flares 54 Spitzer Space Telescope 54 luminosity 54 Gliese 54 sunspots 54 gravitational 54 celestial objects 54 aurora 54 electron 53 infrared radiation 53 orbits 53 starlight 53 electrons 53 suns 53 wavelengths 53 vortices 53 Einstein theory 53 volcanism 52 hydrogen atoms 52 Kuiper Belt 52 general relativity 52 spectroscopic 52 filaments 52 water vapor 52 subatomic particles 51 galactic 51 particles 51 interstellar space 51 asteroids 50 ionosphere 50 Astrophysical Journal 50 protons 50 asteroid 50 deuterium 50 Cassini 50 Galaxies 50 Solar System 50 spectroscopy 50 gaseous 49 asteroid belt 49 molten rock 49 neutrons 49 Uranus 49 Cassini spacecraft 49 outer layers 48 ultraviolet light