Related by context. Frequent words. (Click for all words.) 58 nebula 56 supernova 54 constellation 54 Betelgeuse 54 Pleiades 54 spiral galaxy 53 distant galaxy 53 Arcturus 53 Milky Way 53 Sedna 52 pulsar 52 galaxy 52 aurora 52 Alpha Centauri 52 Spica 51 Andromeda 51 supernovae 50 brown dwarf 50 astronomers 50 quasar 49 gamma ray burst 49 neutron star 49 supernovas 49 Uranus 49 fainter 49 planet orbiting 49 XMM Newton 48 exoplanet 48 nebulae 48 brown dwarfs 48 redshift 48 constellations 48 Milky Way galaxy 48 planets orbiting 47 pulsars 47 Aldebaran 47 sunspot 47 Saturn rings 47 Spitzer Space Telescope 47 ringed planet 47 Big Dipper 47 Gliese 46 Enceladus 46 galaxies 46 gamma ray bursts 45 distant galaxies 45 planets 45 exoplanets 45 extrasolar planets 45 quasars 44 Regulus 44 infrared radiation 44 comet 44 Astronomers 44 supermassive black hole 44 meteor shower 44 orbits 44 infrared wavelengths 44 NASA Cassini spacecraft 44 Sagittarius 44 Pollux 44 cosmic microwave background 43 celestial 43 Solar System 43 auroras 43 Nebula 43 crescent moon 43 spectra 43 Very Large Telescope 43 galaxy clusters 43 astrophysicists 42 magnetic fields 42 ionosphere 42 rocky planets 42 starlight 42 Aurora Borealis 42 Cassini 42 meteors 41 SDSS 41 NASA Chandra 41 Perseids 41 orb 41 telescope 41 GRB 41 equatorial 41 celestial objects 41 aurora borealis 41 Io 41 luminosity 41 gamma rays 40 crescent 40 orbiting 40 starry sky 40 cosmic ray 40 solar flares 40 interstellar space 40 corona 40 asteroid 40 celestial bodies 40 neutron stars 40 Galaxies