Related by context. Frequent words. (Click for all words.) 64 XMM Newton 63 Galaxy Evolution 62 Hubble observations 61 SDSS 61 COROT 61 spectroscopic 60 supernova remnants 60 microlensing 60 elliptical galaxies 59 planetary nebulae 59 Orion Nebula 59 redshift 59 WMAP 59 WM Keck Observatory 58 globular clusters 58 planetary nebula 58 Type Ia supernovae 58 solar corona 58 galaxy cluster 57 Andromeda galaxy 57 galaxy formation 57 SPIRE 57 astronomical objects 57 X ray emission 57 distant galaxies 57 NASA Cassini spacecraft 57 Milky Way Galaxy 57 supernovae 57 supernova remnant 56 THEMIS 56 NASA ESA Hubble 56 Spitzer Space Telescope 56 Kuiper belt 56 interferometry 56 Keck Observatory 56 globular cluster 56 ESO Very Large Telescope 56 extrasolar planets 55 comet nucleus 55 OGLE 55 quasars 55 galaxy clusters 55 numerical simulations 55 GRBs 55 astrophysicists 55 Gemini Observatory 55 astronomers 55 galaxies 55 IceCube 55 extrasolar planet 55 Pan STARRS 55 quasar 55 dwarf galaxy 54 infrared wavelengths 54 astrophysical 54 Andromeda Galaxy 54 Large Magellanic Cloud 54 NASA Chandra 54 COBE 54 OSIRIS 54 cosmic microwave background 54 auroral 54 brown dwarfs 54 super Earths 54 Mimas 54 ejecta 54 nebulae 54 Saturn rings 54 solar nebula 54 magnetar 54 Crab Nebula 53 distant galaxy 53 gravitational lensing 53 EPOXI 53 exoplanets 53 Space Telescope 53 NICMOS 53 gravitational wave 53 celestial objects 53 Voyager spacecraft 53 Cancri 53 VLBA 53 Milky Way galaxy 53 Milky Way 53 spiral galaxies 53 photometric 52 terrestrial planets 52 GRB # 52 moon Charon 52 astronomical observations 52 dwarf galaxies 52 morphologies 52 optical telescopes 52 planets circling 52 rocky planets 52 nebula 52 Lick Observatory 52 planets orbiting 52 spectra 52 supernova explosions 52 LCLS