Related by context. Frequent words. (Click for all words.) 60 cosmic microwave background 59 galaxy formation 58 X ray emission 57 XMM Newton 57 observable universe 57 Crab Nebula 57 high temperature superconductivity 57 cosmologists 56 astrophysicists 56 Gamma ray bursts 55 Michael A'Hearn 55 astronomers 55 Gliese #g 55 galaxy cluster 55 gravitational lensing 55 spacetime 55 solar nebula 55 Saturn rings 55 dwarf galaxy 55 elliptical galaxies 54 gamma ray burst 54 interstellar dust 54 spectroscopic 54 supernova remnant 54 physicists 54 GRBs 53 GRB # 53 quasars 53 globular cluster 53 Eta Carinae 53 supernova explosions 53 HD #b [002] 53 Cassini Huygens 53 COROT 52 Iapetus 52 galaxy clusters 52 magnetar 52 distant galaxies 52 supernovae 52 Astrophysicist 52 supernova explosion 52 quasar 52 planetary scientist 52 antiprotons 52 infrared wavelengths 52 positron 52 Space Telescope 52 comet nucleus 51 superfluidity 51 Chandra X ray 51 supersymmetry 51 gravitational wave 51 WMAP 51 astronomer 51 supernova remnants 51 journal Astronomy 51 Astrophysical Journal Letters 51 planetary science 51 comet Wild 51 Astrophysical Journal 51 WIMPs 51 muon 51 galaxies 51 astrophysical 51 dwarf galaxies 51 distant galaxy 51 singularities 51 redshift 51 extrasolar planets 51 planetary nebula 51 extrasolar planet 51 astronomical objects 51 X ray Observatory 51 globular clusters 51 gamma ray bursts 50 Pan STARRS 50 Haumea 50 orbiting telescope 50 quantum mechanics 50 NASA Cassini spacecraft 50 spacecraft orbiting 50 neutron stars 50 A'Hearn 50 planet orbiting 50 pulsar 50 astronomical observations 50 Niels Bohr Institute 50 particle physicists 50 Milky Way Galaxy 50 comet 50 Hubble Telescope 50 COBE 50 cosmologist 50 cosmic rays 50 high temperature superconductors 50 gravitational waves 50 Cassini imaging 50 optical telescopes 50 pulsars 50 Andromeda galaxy 50 muons