Related by context. Frequent words. (Click for all words.) 60 X ray emission 59 globular cluster 59 planetary nebulae 59 accretion disk 59 spiral galaxy 59 nebula 58 auroral 58 aurorae 57 Kuiper belt 57 planetary nebula 57 constellation Leo 57 Andromeda galaxy 57 iridescence 57 solar corona 56 constellation Orion 56 active galactic nuclei 56 visible wavelengths 56 Andromeda Galaxy 56 nebulae 56 whorl 56 constellation Perseus 56 spiral galaxies 56 supernova remnant 56 WASP #b 56 starbursts 56 dwarf galaxy 56 ecliptic 56 magnetar 55 Crab Nebula 55 ionized gas 55 elliptical galaxies 55 haloes 55 comet tail 54 planet orbits 54 spacetime 54 supernova remnants 54 interstellar dust 54 galaxy cluster 54 sepals 54 Milky Way Galaxy 54 colliding galaxies 54 bluish 54 polar vortex 54 Oort Cloud 54 magnetars 54 ellipse 53 globular clusters 53 cirrus 53 ringed planet 53 heliosheath 53 stippled 53 iridescent blue 53 striations 53 reddish purple 53 Fomalhaut 53 star Gliese 53 GRB # 53 Orion Nebula 53 Milky Way galaxy 53 reddish hue 52 supernova explosions 52 supergiant 52 distant galaxies 52 orbiting planets 52 luminous 52 whorls 52 HD #b [002] 52 supernova explosion 52 anisotropy 52 convective 52 phosphorescence 52 Enceladus 52 constellations 52 Gamma ray bursts 52 Iapetus 52 Saturn rings 52 Valles Marineris 52 fluorescing 52 ejecta 52 Earth magnetosphere 52 Hubble observations 52 XMM Newton 51 galaxies 51 observable universe 51 distant galaxy 51 Mimas 51 magnetic reconnection 51 GRBs 51 occultation 51 dwarf galaxies 51 astronomical objects 51 unaided eye 51 innermost planet 51 infrared wavelengths 51 reddish 51 umbra 51 Large Magellanic Cloud 51 coppery 51 galaxy formation 51 photometry 50 Type Ia supernovae