Related by context. Frequent words. (Click for all words.) 74 supernova explosion 73 nebula 68 spiral galaxies 67 supernovae 67 globular clusters 67 spiral galaxy 67 nebulae 66 galaxies 66 galaxy cluster 65 quasar 64 supernova 64 Milky Way Galaxy 63 quasars 63 neutron star 63 Milky Way galaxy 63 brown dwarf 63 interstellar medium 63 HD #b [002] 63 distant galaxy 62 planet orbiting 62 galaxy 62 supernovas 62 brown dwarfs 61 gamma ray burst 61 supermassive black hole 61 dwarf galaxies 61 supermassive black holes 60 galaxy clusters 60 Milky Way 60 neutron stars 59 distant galaxies 59 Betelgeuse 59 planets 58 pulsar 58 corona 58 comet 58 pulsars 58 planets orbiting 58 comets 57 nuclei 57 Saturn rings 57 XMM Newton 57 Enceladus 57 interstellar dust 56 filaments 56 rocky planets 56 vortices 56 extrasolar planet 56 exoplanets 56 Spitzer Space Telescope 55 exoplanet 55 gamma ray bursts 55 olivine 54 Kuiper Belt 54 sunspot 54 cosmic microwave background 54 ringed planet 54 atoms 54 Solar System 54 infrared wavelengths 54 unaided eye 54 radioactive decay 53 starburst 53 astronomers 53 redshift 53 suns 53 outer layers 53 Cassiopeia 53 extrasolar planets 53 organic molecules 53 luminosity 53 gamma rays 53 magnetosphere 52 astrophysical 52 Astronomers 52 spacetime 52 gaseous 52 atomic nuclei 52 Uranus 51 constellation 51 dynamical 51 Astrophysical Journal Letters 51 sunspots 51 asteroid belt 51 Galaxies 51 NGC 51 Iapetus 51 particles 51 positrons 51 aurora 51 meteors 51 magnetic fields 51 nova 51 heliosphere 51 cosmic rays 51 auroras 51 outer planets 51 filament 51 interstellar space 51 convective 50 celestial objects