Related by context. Frequent words. (Click for all words.) 58 X ray emission 55 Crab Nebula 55 HD #b [002] 54 galaxy cluster 53 supernova explosion 52 accretion disk 52 gamma ray burst 52 Orion Nebula 52 Cancri 52 distant galaxy 52 supermassive black hole 52 GRBs 52 magnetar 51 planet orbits 51 infrared wavelengths 51 supernova remnant 50 distant galaxies 50 nebula 50 Eta Carinae 50 femtoseconds 50 quasar 50 ringed planet 50 extrasolar planet 49 quasars 49 XMM Newton 49 neutron star 49 picoseconds 49 comet nucleus 49 Saturn moons 49 dwarf galaxy 49 galaxies 49 Saturn rings 48 comet 48 brown dwarf 48 galaxy 48 redshift 48 laser pulse 48 Cassini 48 Cassini orbiter 48 interstellar dust 48 Saturn moon 47 Iapetus 47 perigee 47 supernova explosions 47 cosmic microwave background 47 gamma ray bursts 47 auroral 47 fainter 47 Andromeda galaxy 47 Jupiter Saturn Uranus 46 constellation Perseus 46 supernova 46 NASA Cassini spacecraft 46 Earth magnetosphere 46 Mimas 46 annular eclipse 46 picosecond 46 Enceladus 46 exoplanets 46 galaxy clusters 46 pulsar 46 ejecta 46 globular cluster 46 WMAP 46 quark gluon plasma 46 Kuiper belt 46 interstellar medium 46 volcanically active 46 substorms 46 spiral galaxy 46 radioactive decay 46 comet Wild 46 infrared telescope 46 coronal mass ejection 45 unaided eye 45 meteoroid 45 gamma rays 45 globular clusters 45 starbursts 45 planet orbiting 45 Betelgeuse 45 Milky Way Galaxy 45 starlight 45 luminosity 45 galaxy formation 45 hot Jupiters 45 Saturn moon Enceladus 45 spacetime 45 elliptical orbit 44 Cassini spacecraft 44 ionized gas 44 Milky Way 44 sunspot 44 elliptical galaxies 44 Large Magellanic Cloud 44 lithosphere 44 orbits 44 ESA Mars 44 magnetosphere 44 superfluid 44 super Earths