Related by context. Frequent words. (Click for all words.) 73 Orion Nebula 66 planetary nebula 65 nebula 65 Crab Nebula 63 Andromeda galaxy 63 constellation Orion 63 Andromeda Galaxy 62 galaxy cluster 62 nebulae 62 spiral galaxy 61 Large Magellanic Cloud 61 Milky Way Galaxy 61 planetary nebulae 60 distant galaxy 60 globular cluster 60 Galaxy Evolution 60 supernova remnant 60 XMM Newton 60 solar corona 59 unaided eye 59 constellation Leo 59 planet orbits 59 colliding galaxies 59 Fomalhaut 58 magnetar 58 supernova remnants 58 Eta Carinae 57 supernova explosion 57 X ray emission 57 Mimas 57 celestial object 57 constellation Perseus 57 galaxy 57 Betelgeuse 57 spiral galaxies 57 ionized gas 57 Cancri 57 dwarf galaxy 56 star Gliese 56 GRB # 56 auroral 56 Kuiper belt 56 Spitzer Space Telescope 56 galaxies 56 Milky Way galaxy 56 planets orbiting 56 Milky Way 56 planet orbiting 56 supernova explosions 55 active galactic nuclei 55 corona 55 ringed planet 55 comet tail 55 brown dwarfs 55 accretion disk 55 celestial objects 55 starbursts 55 astronomical objects 54 interstellar dust 54 globular clusters 54 distant galaxies 54 supernova 54 Pleiades 54 brown dwarf 54 luminosity 54 COROT 54 elliptical galaxies 53 HD #b [002] 53 visible wavelengths 53 extrasolar planet 53 comet nucleus 53 La Silla Chile 53 NASA ESA Hubble 53 planets 53 gamma ray burst 53 supernovae 52 Cassiopeia 52 Solar System 52 quasar 52 quasars 52 torus 52 Algol 52 Hubble observations 52 astronomers 52 planets circling 52 constellation 52 Gamma ray bursts 52 haloes 52 infrared wavelengths 52 galaxy clusters 52 Saturn moon Enceladus 52 NASA Cassini spacecraft 51 solar nebula 51 ejecta 51 Sunspots 51 supermassive black hole 51 orb 51 extrasolar planets 51 X ray beams 51 suns 51 supernovas