Related by context. Frequent words. (Click for all words.) 66 NASA Chandra 66 optical telescopes 65 XMM Newton 63 X ray Observatory 62 GRBs 62 X ray emission 62 telescopes 61 Spitzer Space Telescope 61 astronomers 60 quasars 60 astronomical observations 60 gamma ray bursts 59 Very Large Telescope 59 observatories 59 gravitational lensing 59 brown dwarfs 59 globular clusters 59 distant galaxies 59 Space Telescope 59 astronomical objects 59 galaxy clusters 58 WM Keck Observatory 58 pulsars 58 Orion Nebula 58 gamma ray burst 58 redshift 58 elliptical galaxies 58 extrasolar planets 57 Very Large Array 57 infrared telescope 57 supernova remnant 57 planets orbiting 57 spectroscopic 57 supernovae 57 gravitational waves 56 interferometer 56 galaxies 56 dwarf galaxies 56 Eta Carinae 56 telescope 56 exoplanet 56 magnetar 56 distant galaxy 56 supernova explosions 55 NASA Cassini spacecraft 55 supernovas 55 rocky planets 55 super Earths 55 optical telescope 55 infrared wavelengths 55 globular cluster 55 ESO Very Large Telescope 55 Astronomers 55 Saturn moon Enceladus 54 gravitational wave 54 galaxy cluster 54 quasar 54 exoplanets 54 Betelgeuse 54 Andromeda Galaxy 54 Milky Way Galaxy 54 astrophysicists 54 Telescope 54 COROT 54 HD #b [002] 54 terrestrial planets 54 planet orbiting 54 dwarf galaxy 54 neutron stars 53 adaptive optics 53 extrasolar planet 53 Gamma Ray 53 interferometry 53 Large Magellanic Cloud 53 Spectrometer 53 supernova explosion 53 WIMPs 53 nebulae 52 cosmic microwave background 52 Saturn moons 52 Saturn rings 52 WMAP 52 cosmic ray 52 remote sensing satellites 52 spectra 52 spectrometers 52 CMEs 52 Milky Way galaxy 52 meteoroids 52 geomagnetic storms 52 hot Jupiters 51 planets 51 ejecta 51 cosmic rays 51 satellites 51 spiral galaxies 51 solar flares 51 Andromeda galaxy 51 supernova 51 Computer simulations 51 gamma rays