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A cluster of stars held together by their own gravity, and apparently dark matter as well.
- Browse Related Terms: Cluster, Density Fluctuations in Matter, Galaxy, Globular Clusters, Inhomogeneity, Large Scale Structure, local group, Structure, Super Cluster
Created by nuclear reactions, this is the most energetic electromagnetic radiation emitted by the Sun.
- Browse Related Terms: 171, Electromagnetic Spectrum, Faculae, Gamma Rays, Infrared, Infrared (IR) Radiation, Ionization, radiation, Radio Waves, Solar Flare, Solar Ultraviolet Irradiance, Spectrograph, spectrum, Ultraviolet, Visible Light, Wavelength, X-Rays
All > Science > Astronomy > Astrophysics
- See Relativity.
- Browse Related Terms: Aberration, Big Bang, Cosmological Principle, Curvature of Spacetime, General Relativity, Hubble's Law, Milky Way, Quasar, Recede, Relativity, Spacetime, Supernova
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A model of the universe, believed by Aristotle, and Ptolemy which puts the earth at the center.
- Browse Related Terms: Background Radiation, Closed Universe, COSMIC, Cosmic Microwave Backgroun (CMB), Cosmology, Flat Universe, Flatness Problem, Geocentric, Geometries, Heliocentric, Metastable Energy Density, Omega, Ω, Opaque to Radiation, Open Universe , Ω, Planck Time, Universe, Vacuum Energy
All > Science > Astronomy > Astrophysics
Models of the curvature of the universe in which the laws of geometry are like those that would apply on flat, spherical, or saddle-shaped surfaces.
- Browse Related Terms: Background Radiation, Closed Universe, COSMIC, Cosmic Microwave Backgroun (CMB), Cosmology, Flat Universe, Flatness Problem, Geocentric, Geometries, Heliocentric, Metastable Energy Density, Omega, Ω, Opaque to Radiation, Open Universe , Ω, Planck Time, Universe, Vacuum Energy
Refers to an orbit (about 22,300 miles above Earth’s surface) with a period equal to one day. A satellite in geosynchronous orbit above Earth's equator will stay over the same point on Earth at all times. Communications satellites are often put in geosynchronous orbits so that satellite dishes on earth can remain pointed at the same point in the sky at all times.
- Browse Related Terms: AURORA, Auroral Oval, Coronal Mass Ejection (CME), Geosynchronous, Heliosphere, Magnetic Field, Magnetic Field Lines, Magnetic Storms and Substorms, Magnetosphere, Magnetotail, Radiation Belt, Solar System, Solar Wind, Space Weather
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All > Science > Astronomy > Astrophysics
A collection of hundreds of thousands of old stars held together by gravity.
- Browse Related Terms: Cluster, Density Fluctuations in Matter, Galaxy, Globular Clusters, Inhomogeneity, Large Scale Structure, local group, Structure, Super Cluster
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The carrier particle of the strong interactions. It holds quarks together and the atom's nucleus together.
- Browse Related Terms: c, speed of light, Elementary Particle Physics, Fundamental Interactions, Fundamental Particles, Gluon, Gravitational Attraction, Last Scattering Surface, Mass Defect, Meson, Particle Accelerators, Particle Physics, Photon, Quark, radiation, Strong Force
Short-lived cells of plasma that carry heat to the Sun’s surface via convection (rising and falling).
- Browse Related Terms: Convective Zone, Granules, Irradiation, Solar Spectral Irradiance (SSI), Sunspot Cycle, Total Solar Irradiance
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The interaction of particles due to their mass/energy.
- Browse Related Terms: c, speed of light, Elementary Particle Physics, Fundamental Interactions, Fundamental Particles, Gluon, Gravitational Attraction, Last Scattering Surface, Mass Defect, Meson, Particle Accelerators, Particle Physics, Photon, Quark, radiation, Strong Force