Related by context. Frequent words. (Click for all words.) 72 pulsars 67 brown dwarfs 67 globular clusters 67 GRBs 66 super Earths 66 pulsar 64 dwarf galaxy 64 neutron stars 64 galaxy clusters 64 exoplanets 63 galaxies 63 extrasolar planets 63 dwarf galaxies 63 elliptical galaxies 63 quasars 63 supernova explosion 62 quasar 62 supernova explosions 62 gamma ray bursts 62 Eta Carinae 62 supernovae 62 planets 61 neutron star 61 supernovas 61 rocky planets 60 supermassive black holes 60 gamma ray burst 60 distant galaxies 60 orbits 60 supernova 60 spiral galaxies 60 XMM Newton 60 planets orbiting 60 Saturn rings 59 nebulae 59 distant galaxy 59 galaxy cluster 59 optical telescopes 59 Milky Way Galaxy 59 gravitational waves 59 astronomers 58 cosmologists 58 gravitational lensing 58 brown dwarf 58 gravitationally 58 nebula 58 extrasolar planet 58 atomic nuclei 57 planet orbiting 57 HD #b [002] 56 Milky Way galaxy 56 neutrons 56 cosmic microwave background 56 redshift 56 exoplanet 56 ejecta 56 Orion Nebula 56 Milky Way 56 spacetime 55 magnetic fields 55 galaxy 55 nuclei 55 spiral galaxy 55 interstellar dust 55 atomic particles 55 Sedna 55 wavelengths 55 positrons 55 X ray Observatory 55 terrestrial planets 55 gamma rays 54 cosmic rays 54 moons 54 Betelgeuse 54 cosmic ray 54 comets 54 Astronomers 54 filaments 54 atoms 54 astrophysicists 54 Spitzer Space Telescope 54 coronal mass ejections 54 supermassive black hole 53 laser pulses 53 interferometry 53 subatomic particles 53 comet nucleus 53 celestial objects 53 neutrinos 53 spectra 53 outer planets 53 photons 53 CMEs 53 unaided eye 52 asteroids 52 celestial bodies 52 NASA Chandra 52 infrared wavelengths 52 cosmic dust 52 deuterium 52 comet