Related by context. Frequent words. (Click for all words.) 68 gamma ray burst 67 GRBs 66 X ray emission 64 magnetar 63 gamma ray bursts 63 Crab Nebula 63 XMM Newton 62 Gamma ray bursts 61 auroral 61 supernova remnant 60 GRB 60 supernova explosion 60 gamma rays 59 Eta Carinae 59 quasars 58 quasar 57 supernova 57 substorms 57 microlensing 57 distant galaxy 57 accretion disk 57 X ray telescope 57 dwarf galaxy 57 interferometry 57 cosmic ray 57 galaxy cluster 56 gravitational wave 56 redshift 56 gamma ray 56 celestial object 56 ionized gas 56 supernovae 56 ejecta 55 laser pulse 55 z = 55 amplitudes 55 gravitational waves 55 supermassive black hole 55 aurora 55 planet orbiting 55 globular cluster 55 occultation 55 Large Magellanic Cloud 54 Andromeda galaxy 54 infrared wavelengths 54 visible wavelengths 54 coronal mass ejection 54 GeV 54 FRET 54 supernovas 54 HD #b [002] 54 supernova explosions 54 auroras 54 meteoroid 54 laser pulses 54 NICMOS 53 gravitational lensing 53 Fluorescence 53 nebula 53 X ray Observatory 53 Orion Nebula 53 spectra 53 NASA Chandra 53 infrared telescope 53 subatomic particle 53 Very Large Array 53 neutrino 53 Gamma Ray 53 ESO Very Large Telescope 53 extrasolar planet 53 Milky Way Galaxy 53 brown dwarf 53 comet nucleus 52 Spectrometer 52 spectrometer 52 muon 52 pulsars 52 Earth magnetosphere 52 galaxy clusters 52 COROT 52 infrared radiation 52 WIMPs 52 excitation 52 exoplanet 52 WMAP 52 WM Keck Observatory 52 spectroscopic 52 OGLE 52 Andromeda Galaxy 52 cosmic rays 52 CMEs 52 solar flares 52 galaxies 52 pulsar 52 interferometer 51 cosmic microwave background 51 ionosphere 51 distant galaxies 51 observable universe 51 EPOXI 51 optical telescopes