Related by context. Frequent words. (Click for all words.) 52 galaxy cluster 50 XMM Newton 49 quasar 49 elliptical galaxies 48 globular clusters 48 quasars 48 brown dwarf 48 gamma ray burst 48 HD #b [002] 48 supermassive black hole 47 X ray Observatory 47 galaxy clusters 46 brown dwarfs 46 planet orbiting 45 Gliese 45 pulsar 45 redshift 45 exoplanet 45 Enceladus 45 distant galaxy 45 supernovae 45 Spitzer Space Telescope 44 extrasolar planet 44 NASA Chandra 44 neutron star 44 neutron stars 44 galaxies 44 planets orbiting 44 Astronomers 44 gamma ray bursts 43 dwarf galaxies 43 cosmic microwave background 43 WM Keck Observatory 43 infrared wavelengths 43 supernova 43 sunspot 43 galaxy 43 supernova explosion 42 rocky planets 42 astrophysical 42 nebula 42 supernovas 42 astronomers 42 Very Large Telescope 42 Milky Way Galaxy 42 distant galaxies 41 extrasolar planets 41 Milky Way galaxy 41 neutrino 41 Betelgeuse 41 aurora 41 terrestrial planets 41 spiral galaxy 40 nebulae 40 Cassiopeia 40 exoplanets 40 spiral galaxies 40 corona 40 Cassini spacecraft 40 WMAP 40 unaided eye 39 Astrophysics 39 Milky Way 39 Saturn moons 39 pulsars 39 comet 39 astrophysicists 39 Saturn rings 38 cosmic ray 38 gravitational waves 38 CMEs 38 Space Telescope 38 supermassive black holes 37 celestial bodies 37 Sedna 37 NASA Cassini spacecraft 37 Solar System 37 Cassini 37 planets 37 gamma rays 37 Kuiper Belt 36 celestial objects 36 FI 36 orbits 36 Saturn moon 35 solar flares 35 orbiting 35 interstellar dust 35 Astrophysical Journal 35 neutrinos 35 ringed planet 35 Uranus 35 cosmic rays 34 starlight 34 sunspots 34 asteroid 34 HYBRID 34 subatomic particles 33 meteor shower 33 astronomer 33 Astronomy