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(Click for frequent words.) 79 NASA Chandra 68 ESA XMM Newton 66 Spitzer Space Telescope 66 orbiting Chandra 65 X ray observatory 65 quasars 65 X ray telescopes 64 XMM Newton 64 galaxy clusters 63 astronomers 63 optical telescopes 63 X ray observatories 63 distant galaxies 63 active galactic nuclei 62 Astronomers 62 quasar 62 RS Ophiuchi 62 ray Space Telescope 61 gamma ray observatory 61 Fermi telescope 61 X ray emission 60 distant galaxy 60 gamma ray bursts 60 gravitational lensing 60 GRB # 60 RXTE 60 distant quasars 60 RHESSI 59 galaxies 59 magnetars 59 gamma ray burst 59 NASA Wilkinson Microwave 59 supernova explosion 59 Very Large Telescope 59 GRBs 59 AGNs 59 brightest supernova 59 Hubble observations 59 spectroscopic observations 59 starburst galaxies 59 galaxy M# [002] 59 elliptical galaxy NGC 59 Wilkinson Microwave Anisotropy Probe 58 Virgo Cluster 58 globular clusters 58 neutron star 58 gravitational microlensing 58 supermassive 58 supernova remnants 58 distant quasar 58 Very Large Array 58 Space Telescope 58 microlensing 58 colliding galaxies 58 merging galaxies 58 neutron stars 58 Kepler telescope 58 ESA Integral 58 supernova remnant 58 GRB #B 58 WMAP satellite 57 fainter objects 57 Cosmologists 57 CoRoT satellite 57 accretion disks 57 Active Galactic Nuclei 57 SN #gy 57 pulsars 57 Galaxy Evolution 57 protoplanetary disk 57 blazars 57 Astrophysicists 57 WMAP 57 accretion disk 57 galaxy cluster 57 Fomalhaut b 57 RS Oph 57 GALEX 57 magnetar 57 NASA Fermi Gamma 57 WM Keck Observatory 57 X ray binary 57 Evolution Explorer 57 constellation Carina 57 NASA Cassini spacecraft 57 Fermi Gamma ray 57 X ray telescope 57 exoplanetary 57 elliptical galaxies 57 Observatory Very 57 galaxy NGC 57 Type Ia supernova 57 supernovae 56 astrophysicists 56 ESO Very Large Telescope 56 ESO VLT 56 Anisotropy Probe WMAP 56 supermassive black holes 56 Keck Interferometer 56 supermassive black hole 56 dwarf galaxy 56 ROSAT 56 planet orbiting 56 Keck telescopes 56 globular cluster 56 elliptical galaxy 56 Geminga 56 Orion Nebula 56 X ray wavelengths 56 NASA Far Ultraviolet 56 planets orbiting distant 56 XMM Newton satellite 56 gravitational radiation 56 extrasolar 56 Hanny Voorwerp 56 microlensing events 56 Anisotropy Probe 56 proto galaxies 56 Submillimeter Array 56 Red Rectangle 56 Chandra X ray 56 Fermi LAT 56 stellar nurseries 56 gravitational waves 56 UVOT 55 supergiant star 55 protoplanetary disks 55 Corot 7b 55 SN #A 55 SN #C 55 distant supernovae 55 protostars 55 giant elliptical galaxies 55 planetary Transits 55 starburst galaxy 55 Optical Gravitational Lensing Experiment 55 filamentary structure 55 Milky Way halo 55 Gamma ray bursts 55 type Ia supernovae 55 supernova 55 VLTI 55 pulsar 55 cosmic microwave background 55 gravitational lens 55 AU Mic 55 millisecond pulsars 55 infrared observatory 55 planetary nebulae 54 PSR J# 54 Mauna Kea Hawaii 54 gaseous planet 54 ULIRGs 54 extrasolar planets orbiting 54 NASA Interstellar Boundary 54 Using ESO Very 54 red supergiants 54 Keck telescope 54 moons orbiting 54 brown dwarfs 54 Planetary Transits 54 blazar 54 millisecond pulsar 54 barred spiral galaxy 54 galactic mergers 54 infrared telescope 54 Earth magnetosphere 54 exoplanets orbiting 54 cosmic microwave radiation 54 type Ia supernova 54 radial velocity 54 planemos 54 rocky planets 54 La Silla Chile 54 Beta Pictoris 54 reionization 54 planets orbiting 54 Henize #-# 54 coronagraph 54 HD #b [002] 54 BLG #Lb 54 protostar 54 astronomical observations 54 KBOs 54 cosmic magnifying glass 54 galaxy M# [001] 54 galactic clusters 54 Triangulum Galaxy 54 Ulysses spacecraft 54 Wilkinson Microwave Probe 54 distant supernovas 54 Climate Experiment GRACE 54 stellar occultations 54 cosmic cannibal 54 AB Aurigae 54 Spitzer infrared spectrograph 54 novae 54 Epsilon Eridani 54 VIRTIS 54 Trifid Nebula 54 Area Telescope LAT 54 Astrophysical Research 54 Convection Rotation 54 globulars 54 luminous galaxies 54 Gravitational waves 53 star Gliese 53 orbiting gamma ray 53 Crab Nebula 53 GJ#b 53 Galileo spacecraft 53 planet HD #b 53 galactic cosmic rays 53 GRB# 53 Eta Carinae 53 Infrared Array Camera 53 intrinsic brightness 53 Keck Observatory 53 Arches Cluster 53 exoplanet 53 interacting galaxies 53 ejecta 53 relativistic jets 53 GJ #b [001] 53 OGLE TR #b 53 Milky Way galaxy 53 galaxies collide 53 Observatory STEREO 53 Bok globules 53 Spectrograph 53 spiral galaxy NGC 53 Seyfert galaxies 53 Small Magellanic Cloud 53 Multi Object Spectrograph 53 solar flares 53 dwarf galaxies 53 Cat Paw Nebula 53 gravitational lenses 53 SN #E 53 OGLE 53 Antennae Galaxies 53 Astrophysical Journal 53 Coma Cluster 53 COROT 53 microquasar 53 active galactic nucleus 53 Lunar Reconnaissance Orbiter LRO 53 Omega Centauri 53 Large Magellanic Cloud 53 X ray emitting 53 planets circling 53 Keck Telescope 53 brown dwarf 53 Neutron stars 53 Virgo cluster 53 proto cluster 53 distant galaxy clusters 53 redshift 53 galactic nuclei 53 submillimetre 53 galactic collisions 53 HESS telescopes 53 HARPS instrument 53 astrophysical objects 53 detect gravitational waves 53 weak gravitational lensing 53 Milky Way Galaxy 53 Planck satellite 53 astronomical objects 53 Kuiper belt objects 53 sunlike star 53 afterglows 53 Nasa Kepler 53 CMB radiation 53 magnetic reconnection 53 sunlike stars 53 IBEX spacecraft 53 Type Ia supernovae 53 Magellanic Clouds 53 Cassini spacecraft 53 comet nucleus 53 X ray afterglow 53 Trojan asteroids 53 HD#b 53 Cosmic Microwave Background 53 interstellar clouds 53 galaxy formation 53 Carina Nebula 53 redshifts 52 circumstellar disk 52 Extraterrestrial Physics 52 Crab Pulsar 52 G#.# +#.# 52 Epsilon Aurigae 52 Saturn moon Enceladus 52 ESO telescope 52 SN#A 52 planets orbiting stars 52 Beta Pictoris b 52 Kailash Sahu 52 spacecraft Cassini 52 Relations Observatory STEREO 52 gravitational interactions 52 NuSTAR 52 Higgs bosons 52 solar corona 52 Cygnus X 52 submillimeter 52 supernovas 52 moon Io 52 spectroscopic measurements 52 Zeta Ophiuchi 52 Neil Gehrels 52 cluster NGC 52 Upsilon Andromedae 52 infrared wavelengths 52 foreground galaxy 52 extrasolar planetary systems 52 globular star 52 Interstellar Boundary Explorer 52 Saturnian moon 52 constellation Hercules 52 transiting planets 52 infrared telescopes 52 planets orbiting sun 52 Subaru telescope 52 binary quasar 52 rotating neutron stars 52 NASA Lunar Reconnaissance 52 occultations 52 Eagle Nebula 52 eclipsing binary 52 TrES 4 52 superclusters 52 Southern Observatory ESO 52 neutron spectrometer 52 Saturn magnetosphere 52 Telescope BAT 52 aurorae 52 Orion nebula 52 faint galaxies 52 Perseus Cluster 52 PSR B# +# 52 HD# [002] 52 extragalactic 52 supernova explosions 52 SINFONI 52 circumstellar disks 52 NASA Kepler 52 planets astronomers 52 Stephan Quintet 52 mu Arae 52 gamma ray telescope 52 Herschel Space 52 exo planets 52 telescope 51 astrophysical 51 cosmic phenomena 51 Near Infrared Camera 51 Lyman alpha 51 infall 51 gravitationally bound 51 gamma ray emission 51 transiting exoplanet 51 cosmologists 51 La Silla observatory 51 V# Mon 51 Planck telescope 51 ESO telescopes 51 Fermi Telescope 51 HARPS spectrograph attached 51 Earthlike planets 51 Io Europa 51 trans Neptunian objects 51 Orbiter MRO 51 GLAST 51 XTE J# 51 Solar Terrestrial Relations 51 PASADENA Calif. Astronomers 51 Hawking radiation 51 interstellar cloud 51 Observatory telescope 51 particle detectors 51 Bug Nebula 51 quark gluon plasma 51 Cosmic Microwave Background CMB 51 Hubble Space Telescopes 51 Pluto Charon 51 Supernova #A 51 orbiting Saturn 51 NGC# 51 cosmological distances 51 GROND 51 icy moons 51 permanently shadowed craters 51 sized planets orbiting 51 X ray pulses 51 energetic gamma rays 51 telescopes 51 SWIFT J#.# 51 exoplanets 51 constellation Cassiopeia 51 gamma rays 51 chemical abundances 51 Science Experiment HiRISE 51 astrophysical phenomena 51 multiband imaging photometer 51 Burst Alert 51 extrasolar planet 51 STIS 51 submillimetre wavelengths 51 extrasolar planets 51 Surveys ACS 51 Gravitational lensing 51 CoRoT 7b 51 Comet Holmes 51 X ray spectrometer 51 Infrared Pathfinder Satellite 51 exoplanet hunter 51 Multi Object Spectrometer 51 transiting exoplanets 51 earthshine 51 Tod Strohmayer 51 moon Enceladus 51 GJ #b [002] 51 jovian 51 gravitationally lensed 51 Lagoon Nebula 51 WISE infrared 51 dwarf spheroidal galaxies 51 optical interferometry 51 Paranal Observatory 51 Upsilon Andromedae b 51 magnetospheric 51 DEEP2 51 cosmological parameters 51 Cassini flyby 51 red supergiant 51 Explorer WISE 51 gravity warps 51 smallest exoplanet 51 NASA ESA Hubble 51 heavily cratered 51 supersymmetric particles 51 spiral galaxy 51 Adam Riess 51 Wolf Rayet star 51 THEMIS satellites 51 Cassini Huygens 51 LOFAR 51 HiRISE camera 50 gamma ray telescopes 50 Gemini telescopes 50 P/# A2 50 Astrophysical 50 proplyds 50 WISE telescope 50 HIRES spectrometer 50 radial velocity method 50 XMM Newton X ray 50 stellar seismology 50 nebular 50 NASA Hubble Space 50 Large Telescope 50 Kuiper belt object 50 Space Telescope GLAST 50 orbiting 50 cosmic rays 50 Orbiter LRO 50 Hubble Space Telescope HST 50 ionized gas 50 Comet 9P/Tempel 1 50 polarimetry 50 dust enshrouded 50 Lunar Prospector 50 Ultraviolet Optical Telescope 50 J#.# [001] 50 spectroscopic 50 galactic cores 50 particle physics experiments 50 orbiting observatories 50 spiral galaxies 50 VLBA 50 Kepler #b 50 Type 1a supernovae 50 maser emission 50 giant elliptical galaxy 50 Tarantula Nebula 50 Vikhlinin 50 protoplanet 50 star Fomalhaut 50 Richard Mushotzky 50 SIRTF 50 NASA twin STEREO 50 Subaru Telescope 50 Spitzer infrared 50 constellation Centaurus 50 nebulae 50 submillimeter wavelengths 50 Pierre Auger Observatory 50 telescopes astronomers 50 spatially resolved 50 super Earths 50 interstellar dust 50 Moderate Resolution Imaging 50 UCO Lick 50 Bullet Cluster 50 planet magnetosphere 50 Great Observatories 50 Galactic cosmic rays 50 galactic cannibalism 50 electron neutrinos 50 radial velocity technique 50 Solar TErrestrial RElations Observatory 50 planets orbits 50 VISTA telescope 50 La Silla Observatory 50 THEMIS spacecraft 50 Andromeda galaxy 50 MARSIS 50 planetary nebula 50 DIXI 50 Imaging Spectroradiometer MODIS instrument 50 Venusian atmosphere 50 gravitational wave 50 Earth Observation satellites 50 PSR J# +# 50 Cancri 50 SMBH 50 ESA Envisat satellite 50 Cepheid variable 50 lensing galaxy 50 HM Cancri 50 SDSS II 50 Digitized Sky Survey 49 Antenna LISA 49 IceCube 49 infrared spectrograph 49 Astrophysical Journal Letters 49 Saturn moons 49 substorm 49 Einstein theory 49 Collider LHC 49 NASA Mars Odyssey 49 supergiant stars 49 smallest exoplanets 49 BP Psc 49 intracluster 49 spiral galaxy M# 49 TGFs 49 Infrared Thermal Imaging Spectrometer 49 orbiting Hubble Space Telescope 49 constellation Lyra 49 muon neutrinos 49 Voorwerp 49 observatories 49 Ring Nebula 49 Kuiper Belt object 49 solar nebula 49 WASP #b 49 visible wavelengths 49 BP Piscium 49 circumstellar 49 nebula 49 synchrotron x ray 49 axions 49 NASA Gamma ray 49 constellation Virgo 49 NASA STEREO 49 SNR #-#.# 49 retrograde orbit 49 transiting planet 49 astrometry 49 NASA Cassini 49 galactic nucleus 49 Gondolo 49 SOAR telescope 49 Alex Filippenko 49 HL Tau 49 Harvard exoplanet hunter 49 KH #D 49 Supernovae 49 interferometry 49 HARPS spectrograph 49 Descent Imager Spectral Radiometer 49 De Pontieu 49 Field Imager 49 Supermassive black 49 polar vortex 49 radio occultation 49 Interior Laboratory GRAIL 49 Fornax cluster 49 Microlensing 49 CMEs 49 Magnetic Imager HMI 49 STEREO spacecraft 49 optical wavelengths 49 Cygnus Lyra region 49 constellation Eridanus 49 exosolar planets 49 gamma ray 49 Hubble Space Telescope 49 Heterodyne Instrument 49 gamma rays emitted 49 infrared imager 49 Kepler spacecraft 49 proton collisions 49 HUDF 49 NICMOS 49 millimeter wavelengths 49 Viking landers 49 nucleosynthesis 49 auroras 49 Deep Field HUDF 49 Astrophysics Cambridge Mass. 49 Higgs particle 49 Gal Yam 49 spiral galaxy Messier 49 protoplanetary 49 Reflection Radiometer 49 Kuiper belt 49 gravitational interaction 49 Hipparcos 49 supernova SN 49 gravitational tides 49 terrestrial planets 49 superdense 49 exoplanet orbiting 49 galaxy 49 Gemini Observatory 49 coronal loops 49 gamma ray flares 49 ultraviolet wavelengths 49 #gy 49 cometary dust 49 Cosmic Background Explorer 49 Observatory SDO 49 numerical simulations 49 oppositely directed 49 Gliese #e 49 exo planet 49 neutrinos 49 Cloud Aerosol Lidar 49 ESO Paranal Observatory 49 infrared interferometry 49 orbiting spacecraft 49 X ray binaries 49 antimatter particles 49 infrared astronomy 49 spinning neutron 49 galactic disk 48 radiotelescope 48 Sagittarius B2 48 SOHO spacecraft 48 Neutron Detector 48 ESO PR 48 interstellar medium 48 gravitationally 48 gamma ray photons 48 Magnetars 48 infalling 48 Cassini Huygens spacecraft 48 NASA Cosmic Background 48 Comet Hartley 2 48 Solar System 48 lunar crust 48 zodiacal light 48 Hot Jupiters 48 Paranal Chile 48 volcanic moon Io 48 magnetic fields 48 exoplanets planets 48 particle detector 48 STEREO 48 Herschel Space Telescope 48 telescope atop Mauna 48 Nasa spacecraft 48 Samuel Oschin Telescope 48 Helix nebula 48 star Beta Pictoris 48 particle smasher 48 NGC #A 48 NASA Lunar Prospector 48 ringed planet 48 substorms 48 NASA MESSENGER spacecraft 48 neutral mass spectrometer 48 Haumea 48 Milky Way 48 interferometers 48 starquakes 48 Galilean satellites 48 Explorer IBEX 48 Martian craters 48 Neutral Mass Spectrometer 48 impactors 48 Nikku Madhusudhan 48 periodic dimming 48 hydrated minerals 48 interstellar dust clouds 48 NASA WMAP 48 geoneutrinos 48 astronomical telescope 48 exosphere 48 HAT P 48 Resolution Imaging 48 planets comets 48 moon Ganymede 48 planet orbits 48 cosmic ray particles 48 Jupiter moon Io 48 visit http:/saturn.jpl.nasa.gov 48 TNOs 48 Herschel telescope 48 neutrino particles 48 Kepler Space Telescope 48 Fermilab Tevatron 48 NASA Kepler spacecraft 48 Amateur astronomers 48 orbiting observatory 48 Laser Interferometer Gravitational Wave 48 XMM Newton observations 48 AKARI 48 planetary transits 48 habitable planets 48 masers 48 comet McNaught 48 spherical halo 48 TrES 48 NASA Voyager spacecraft 48 Mimas 48 Saturn moon 48 YORP effect 48 rotating neutron 48 VY Canis Majoris 48 Type Ia 48 celestial object 48 GRB #A 48 particle acceleration 48 planets 48 Saturn rings 48 Chandra Observatory 48 phyllosilicates 48 Proxima Centauri 48 photometry 48 noctilucent clouds 48 Andromeda Galaxy 48 ATLAS detector 48 moons Phobos 48 optical telescope 48 Voyager spacecraft 48 auroral emissions 48 Cerro Paranal 48 Giovanni Cassini 48 WFPC2 48 UKIRT 48 gamma ray observatories 48 neutralinos 48 High Accuracy Radial 48 earthlike planets 48 Corot 9b 48 Planck spacecraft 48 Dwarf galaxies 48 coronal mass ejections CMEs 48 Rosette Nebula 48 2MASS 48 blue supergiant 48 sterile neutrino 48 Computer simulations 48 spacecraft orbiting 48 NASA Great Observatories 48 Extrasolar Planet Search 48 Pegasi 48 chondritic meteorites 48 Oort Cloud 48 Cassini 48 CoRoT 9b 48 Auger Observatory 48 Alfven waves 48 Viking orbiters 48 LORRI 48 Galilean moons 48 SN #D 48 UDFy # 48 Cancri e 48 Alycia Weinberger 48 SMBHs 48 interferometric 47 Wolszczan 47 dense neutron stars 47 multiwavelength 47 atop Mauna Kea 47 Astrophysics MOA 47 CERN experiments 47 Telescope LSST 47 shorter wavelengths 47 spectroscopic analysis 47 APXS 47 supercomputer simulations 47 heliosphere 47 spacecraft flyby 47 Earthlike planet 47 planets atmospheres 47 Thermal Emission Spectrometer 47 Type Ic supernova 47 Alfvén waves 47 Ionosphere Sounding 47 electron diffraction 47 High Resolution Imaging 47 fading afterglow 47 XMM Newton observatory 47 EPOXI mission 47 Cosmic Background Explorer COBE 47 baryonic 47 spiral nebulae 47 Explorer GALEX 47 HiRISE image 47 Doradus 47 Comet Hale Bopp 47 auroral 47 Imaging Spectrometer 47 Komossa 47 Butterfly Nebula 47 coronal mass ejections 47 Cepheids 47 Mössbauer 47 ESA Planck 47 faintest galaxies 47 Hubble Ultra 47 VB #b 47 Mars Odyssey spacecraft 47 occulted 47 NASA THEMIS 47 Saturn aurora 47 colliders 47 WIYN 47 planetesimals 47 neutrino detectors 47 infrared mapping spectrometer 47 Envisat satellite 47 spectroscopically 47 #P/Churyumov-Gerasimenko 47 planet Uranus 47 Extrasolar planets 47 ESA SMART 47 CAIs 47 Alpha Particle 47 habitable worlds 47 protons collide 47 Planck 47 moon Titan 47 EPOXI 47 luminosities 47 BLG #L 47 ESA Mars 47 Pieter van Dokkum 47 VIRTIS instrument 47 PKS #-# 47 HiRISE camera aboard 47 Mars Pathfinder lander 47 filamentary structures 47 SNe 47 orbiting Cassini spacecraft 47 Sgr 47 CoRoT 47 Type Ia supernovas 47 redshifted 47 relativistic particles 47 NASA QuikScat satellite 47 innermost planet 47 gamma ray radiation 47 cosmic ray 47 subatomic particle 47 SPICAM 47 comets orbiting 47 Deep Impact eXtended Investigation 47 celestial phenomena 47 planets moons 47 Astrophysics 47 Wide Angle Search 47 cosmic ray observatory 47 Heliospheric Observatory SOHO 47 Delta Cephei 47 chondrules 47 Solar Orbiter 47 AERONET 47 Exoplanets 47 gravitational 47 optical spectra 47 faraway galaxies 47 Tycho supernova remnant 47 IRAS 4B 47 optical microscopy 47 Mars Reconnaissance Orbiter MRO 47 imaging spectrometer 47 Gliese #d 47 planet TrES 47 APEX telescope 47 orbiting telescopes 47 Fomalhaut 47 Compact Reconnaissance Imaging Spectrometer 47 asteroseismology 47 Oort cloud 47 comet Hartley 2 47 INTEGRAL 47 OMEGA instrument 47 magnetosphere 47 particle accelerators 47 Gliese #c 47 emit X rays 47 WIMPs 47 Array ALMA 47 planetary nebulas 47 Muchachos Observatory 47 Diviner 47 arcminutes 47 Veil Nebula 47 chromosphere 47 Climate Experiment 47 Atacama Large Millimeter Array 47 geochemists 47 Dumbbell Nebula 47 ESA Herschel 47 muons 47 Earths orbiting 47 Super Kamiokande 47 Aram Chaos 47 RX J# 47 Gamma Ray 47 WFC3 47 LIGO 47 general relativity 47 Interferometer 47 HII regions 47 NASA Kepler telescope 47 Planetary Science Institute 47 hexagonal mirrors 47 interstellar particles 47 Arecibo telescope 47 photoemission 47 inhabitable planets 47 VHE gamma rays 47 sodium atoms 47 Omega Nebula 47 coronal mass ejection 47 aboard ESA Envisat 47 lunar perigee 47 ESA Cluster 47 astrometric 47 COROT 7b 47 volcanically active 47 Solar Dynamics Observatory 47 GLAST Burst Monitor 47 Chile La Silla 47 SDSS III 47 Telescope 47 MPG ESO 47 gamma ray burst GRB 47 ultraviolet imaging spectrograph 47 subatomic particles 47 refurbished Hubble Space 47 orbited Jupiter 47 Spectrometer 47 Atacama Large Millimeter submillimeter 47 Laser Interferometer Space 47 Kepler Mission 47 Sagittarius dwarf galaxy 47 Cerro Tololo 46 SEGUE 46 LRO spacecraft 46 Hinode 46 Cerro Paranal Chile 46 GQ Lupi 46 Grillmair 46 gamma ray bursts GRBs 46 outer corona 46 flyby spacecraft 46 journal Astronomy 46 astronomer Clyde Tombaugh 46 Gamma ray bursts GRBs 46 Sensing Satellite LCROSS 46 RHIC 46 Ranging spacecraft 46 Extragalactic 46 moonlets 46 ALFALFA 46 interferometric technique 46 proton antiproton collisions 46 stellar occultation 46 Carina constellation 46 Famed astrophysicist Stephen Hawking 46 HD# [005] 46 planets Uranus 46 Earthlike 46 Resolution Stereo Camera 46 interstellar molecules 46 CoRoT #b 46 ultraluminous galaxy 46 Gamma ray Burst