Related by context. Frequent words. (Click for all words.) 75 planets orbiting 69 exoplanets 68 exoplanet 68 rocky planets 67 brown dwarf 65 supernova 65 distant galaxy 65 extrasolar planets 64 Gliese 64 Milky Way galaxy 64 gamma ray burst 63 planets 63 brown dwarfs 63 neutron star 63 spiral galaxy 63 pulsar 63 quasar 62 nebula 61 supernovae 60 astronomers 60 Milky Way 60 supermassive black hole 60 galaxy 60 galaxies 60 Betelgeuse 59 Sedna 59 quasars 59 gamma ray bursts 59 pulsars 59 comet 58 Astronomers 58 dwarf galaxies 57 distant galaxies 57 orbiting 57 Iapetus 57 orbits 57 Spitzer Space Telescope 57 galaxy clusters 56 X ray Observatory 56 neutron stars 56 neutrino 56 redshift 56 Enceladus 56 XMM Newton 55 UB# [003] 55 nebulae 55 fainter 55 quark 55 moon Titan 55 supernovas 55 asteroid 54 habitable zone 54 Alpha Centauri 53 supermassive black holes 53 Very Large Telescope 53 NASA Chandra 53 planetary 53 ringed planet 52 celestial objects 52 Astrophysical Journal Letters 52 comets 52 gravitational waves 52 infrared wavelengths 52 Solar System 51 Saturn rings 51 astrophysicists 51 Astrophysical Journal 51 NASA Cassini spacecraft 51 cosmic ray 51 spectroscopic 51 gamma rays 51 Uranus 51 adaptive optics 51 spectra 51 planet 51 Saturn moon 50 asteroids 50 corona 50 celestial bodies 50 dwarf planet 50 positrons 50 sunspot 50 astrophysical 50 luminosity 50 solar flares 49 neutrinos 49 asteroid belt 49 Cassini spacecraft 49 heliosphere 49 cosmic microwave background 49 meteorite 49 Earths 49 telescope 49 Kuiper Belt 49 organic molecules 49 cosmic rays 49 Pleiades 49 orbited 49 Cassiopeia 49 moons 49 Tempel 1