Related by context. Frequent words. (Click for all words.) 61 constellations 54 Cassiopeia 54 Pleiades 53 nebula 53 Scorpius 52 Betelgeuse 51 galaxy 51 nebulae 51 Milky Way Galaxy 51 spiral galaxy 49 orbits 49 Sagittarius 48 crescent moon 48 occultation 47 Arcturus 47 orbiting 47 globular clusters 47 crescent 46 telescope 46 Ophiuchus 46 Spica 46 planet orbiting 45 firmament 45 Milky Way 45 supernova 45 celestial 45 supernova explosion 45 orbited 45 ringed planet 44 Alpha Centauri 44 XMM Newton 44 Milky Way galaxy 44 planets 44 Andromeda 44 celestial objects 44 Pollux 44 unaided eye 44 fainter 44 Ursa Major 44 cosmos 44 Uranus 44 terrestrial planets 43 gamma ray burst 43 supernovas 43 orbit 43 distant galaxy 43 GRBs 43 Big Dipper 43 planets orbiting 42 Nebula 42 galaxies 42 zodiac 42 Regulus 42 Pisces 42 galactic 42 cosmological 42 spiral galaxies 42 galaxy cluster 42 supernovae 42 elliptical galaxies 42 HD #b [002] 42 optical telescopes 42 elliptical orbit 42 Spitzer Space Telescope 41 cluster 41 satellite constellation 41 Earth orbit 41 circular orbit 41 celestial bodies 41 quasar 41 brown dwarf 41 meteor shower 41 satellites 41 astronomers 41 infrared wavelengths 41 quasars 41 luminosity 40 orbital 40 universe 40 telescopes 40 WMAP 40 penumbra 40 pulsar 40 brown dwarfs 40 perigee 40 astrophysical 40 Constellations 40 Space Telescope 40 starlight 40 extrasolar planet 39 gamma ray bursts 39 ellipse 39 astrological 39 cosmic microwave background 39 extrasolar planets 39 planet 39 supermassive black hole 39 aurora borealis 39 Sedna 39 moon 39 interferometer