Related by context. Frequent words. (Click for all words.) 72 quasar 72 quasars 71 gamma ray burst 71 supermassive black hole 70 neutron star 70 galaxy clusters 68 supernovae 68 galaxies 68 XMM Newton 68 gamma rays 67 supernova 67 nebula 66 pulsar 66 gamma ray bursts 66 neutron stars 66 supermassive black holes 65 distant galaxies 65 gravitational waves 65 interstellar medium 65 pulsars 65 infrared wavelengths 64 interstellar dust 64 magnetic fields 64 cosmic rays 64 dwarf galaxies 64 globular clusters 64 supernovas 64 spiral galaxies 63 cosmic ray 63 brown dwarfs 63 redshift 62 brown dwarf 62 magnetosphere 62 cosmic microwave background 62 gamma ray 62 planet orbiting 62 nebulae 62 corona 61 aurora 61 distant galaxy 61 Enceladus 61 rocky planets 61 sunspot 61 spiral galaxy 61 X ray Observatory 60 extrasolar planets 60 Saturn rings 60 Milky Way galaxy 60 astronomers 60 spectra 60 comet 60 Milky Way 60 volcanism 60 mid latitudes 60 neutrino 59 solar flares 59 convective 59 astrophysical 59 auroras 59 GRB 59 heliosphere 59 CMEs 59 galaxy 59 infrared radiation 59 spectroscopic 59 neutrinos 59 comets 59 sunspots 58 positrons 58 NASA Chandra 58 wavelengths 58 Betelgeuse 58 NASA Cassini spacecraft 58 olivine 58 astrophysicists 57 planets orbiting 57 dynamical 57 magnetization 57 exoplanet 57 luminosity 57 laser pulse 57 water vapor 57 Iapetus 57 ionosphere 57 atmospheric circulation 56 photons 56 atomic nuclei 56 troposphere 56 laser pulses 56 gravitational 56 neutrons 56 exoplanets 55 planets 55 vortices 55 nuclei 55 oscillations 55 filaments 55 convection 55 Spitzer Space Telescope 54 ringed planet 54 geomagnetic field