Related by context. Frequent words. (Click for all words.) 64 astrophysical 63 astronomical objects 61 galaxy formation 61 XMM Newton 60 astronomical observations 59 gravitational wave 59 outer planets 59 GRBs 59 nebulae 58 celestial objects 58 auroral 58 Gamma ray bursts 58 gravitational lensing 57 COROT 57 supernovas 57 supernovae 57 habitable planets 57 gamma ray bursts 57 globular clusters 57 optical telescopes 56 microlensing 56 planetary missions 56 distant galaxies 56 celestial bodies 56 ionospheric 56 numerical simulations 56 CMEs 56 astrophysicists 56 observatories 56 elliptical galaxies 56 gravitational waves 56 spectroscopic 56 Voyager spacecraft 56 astronomers 56 planets 56 telescopes 55 X ray emission 55 quasars 55 pulsars 55 general relativity 55 accretion disk 54 galaxy clusters 54 Earth magnetosphere 54 supernova explosions 54 CALIPSO 54 neutron stars 54 brown dwarfs 54 atmospheric chemistry 54 terrestrial planets 53 astronomy 53 extrasolar planets 53 coronal mass ejections 53 Hubble Telescope 53 comet nucleus 53 cosmological 53 auroras 53 interferometry 53 cosmic ray 53 photometric 53 galaxies 53 magnetic fields 53 astrophysics 53 gamma ray burst 53 cosmology 53 planetary science 53 Computer simulations 53 Orion Nebula 53 dwarf galaxies 53 LIGO 52 cosmic rays 52 moon Charon 52 spiral galaxies 52 cosmologists 52 globular cluster 52 distant galaxy 52 morphologies 52 NASA Chandra 52 ESO Very Large Telescope 52 interstellar dust 52 gamma rays 52 magnetosphere 52 Saturn rings 52 infrared wavelengths 52 particle accelerators 52 Saturn moons 52 celestial object 52 neutrino 51 planets orbiting 51 Andromeda Galaxy 51 spacetime 51 particle physics 51 Cassini Huygens 51 supernova explosion 51 WM Keck Observatory 51 rocky planets 51 substorms 51 X ray Observatory 51 Andromeda galaxy 51 IceCube 51 planetary 51 subatomic particle