Related by context. Frequent words. (Click for all words.) 59 supernova 48 gamma ray burst 47 planet orbiting 46 aurora 45 supernovae 45 corona 45 distant galaxy 45 Gliese 44 supernovas 44 nebula 43 gamma ray bursts 43 quasar 43 brown dwarf 43 suns 42 galaxy 42 Big Bang 42 pulsar 41 quasars 41 XMM Newton 41 neutron star 41 comet 41 neutron stars 41 Betelgeuse 41 solar flares 41 cosmic ray 41 meteor shower 40 planets orbiting 40 astronomers 40 exoplanets 40 quark 40 luminosity 40 pulsars 40 neutrino 40 nebulae 40 interstellar medium 39 meteor 39 starburst 39 Astronomers 39 X ray Observatory 39 cosmic 39 globular clusters 39 Cassiopeia 39 Alpha Centauri 38 Uranus 38 redshift 38 planets 38 CMEs 38 Gamma Ray 38 exoplanet 38 brown dwarfs 38 galaxies 38 universe 38 auroras 38 gamma ray 38 gamma rays 38 poof 37 extrasolar planets 37 nuclei 37 NASA Chandra 37 Iapetus 37 astrophysicists 37 halo 37 astrophysical 37 atomic particles 37 cometary 37 neutrinos 37 supermassive black hole 36 dynamical 36 cosmic rays 36 positrons 36 moons 36 gaseous 36 infrared wavelengths 36 neutrons 36 Galactic 36 orb 36 Nebula 36 sunspot 36 fainter 36 Asteroid 36 cosmos 36 magnetosphere 36 progenitor 35 WMAP 35 constellation 35 Milky Way Galaxy 35 galaxy clusters 35 proton 35 Halley Comet 35 Spitzer Space Telescope 35 galactic 35 outer layers 35 orbiting 35 celestial 35 radioactive decay 35 infrared radiation 35 cosmic microwave background 35 comets 35 spectroscopic 35 planetary 35 ringed planet