Related by context. Frequent words. (Click for all words.) 65 X ray emission 64 active galactic nuclei 63 Andromeda galaxy 63 magnetar 63 planetary nebulae 62 visible wavelengths 61 galaxy cluster 61 distant galaxy 61 Kuiper belt 60 supernova remnant 60 comet nucleus 60 accretion disk 60 supernova remnants 60 solar corona 60 observable universe 60 spiral galaxy 60 elliptical galaxies 60 supernova explosion 59 supernova explosions 59 globular cluster 59 galaxy clusters 59 nebulae 59 dwarf galaxy 59 planet orbits 59 quasar 59 ionized gas 59 ejecta 59 Andromeda Galaxy 59 Crab Nebula 59 HD #b [002] 59 Eta Carinae 59 galaxy formation 59 spiral galaxies 58 spacetime 58 interstellar dust 58 celestial object 58 Type Ia supernovae 58 gravitational lensing 58 GRBs 58 Hubble observations 58 planet orbiting 58 auroral 58 singularities 58 Milky Way Galaxy 58 torus 58 infrared wavelengths 58 colliding galaxies 57 interferometry 57 haloes 57 Saturn rings 57 redshift 57 rocky planets 57 planetary nebula 57 shorter wavelengths 56 constellation Orion 56 nebula 56 galaxies 56 solar nebula 56 spatial dimensions 56 distant galaxies 56 Orion Nebula 56 dwarf galaxies 56 ecliptic 56 Gamma ray bursts 56 comet tail 56 Gliese #g 56 XMM Newton 56 gravitational wave 56 anisotropy 56 brown dwarfs 56 neutron stars 56 supernovas 55 star Gliese 55 interstellar medium 55 ringed planet 55 astronomers 55 planets 55 astrophysical 55 Earth magnetosphere 55 excitations 55 Milky Way galaxy 55 cosmic microwave background 55 Jupiter moons 55 astronomical objects 55 quasars 55 morphologies 55 planets orbiting 55 gravitational waves 55 Iapetus 55 optical telescopes 54 Saturn moons 54 galaxy 54 supernovae 54 Fomalhaut 54 meteoroids 54 gamma rays 54 accreting 54 gamma ray burst 54 heliosphere 54 COROT 54 gamma ray bursts