CZ:Core Articles > Astronomy

•  Astronomy: The study of objects and processes in the observable universe, e.g. stars, planets, comets or asteroids. [e]
•  Solar system: The sun and the planets orbiting it. [e]
•  Planet: A cosmic body orbiting a star. [e] -- Derek Harkness
•  Moon: The only natural satellite of our planet, Earth. [e] -- Derek Harkness
•  History of Astronomy: Add brief definition or description -- Thomas Simmons
•  Universe: The summation of all particles and energy that exist and the space-time in which all events occur. [e]
•  Andromeda Galaxy: Nearest large spiral galaxy to the Milky Way, also known as Messier 31 [e] -- Thomas Simmons
•  Astrophysics: Hybrid of Physics and Astronomy that attempts to explain the physical workings of the celestial objects and phenomena. [e] -- Thomas Simmons
•  Cosmology: A branch of astronomy and of metaphysics committed to the study of the universe as a whole, of the contents, structure, and evolution of the universe from the beginning of time to the future. [e] -- Thomas Simmons
•  Earth: The third planet from the Sun in our solar system; the only place in the universe known by humanity to harbor life. [e] (also in Earth Sciences - please check CZ talk:Core Articles)
•  Interstellar matter: The gaseous and dust material between the stars. [e] -- Thomas Simmons
•  Johannes Kepler: (1571-1630) German astronomer best known for his three laws of planetary motion. [e]
•  Milky Way: The Milky Way galaxy which contains our solar system. [e]
•  Ptolemy: (2nd century AD) Egyptian astronomer and geographer whose main work, the Almagest, a compendium of contemporary astronomical knowledge, was in use into the 15th century. [e]
•  Star: A massive, luminous ball of plasma that is held together by gravity. [e] -- Thomas Simmons
•  Telescope: Instrument designed for the observation of remote objects by the collection of electromagnetic radiation. [e] -- Thomas Simmons
•  Astronomical Unit: Mean distance from the Earth to the Sun used to provide relative distances within the solar system; value is approx. 150 million kms. [e] -- Thomas Simmons
•  Big Bang: A cosmological theory holding that the universe originated approximately 20 billion years ago from the violent explosion of a very small agglomeration of matter of extremely high density and temperature. [e] -- Thomas Simmons
•  Black hole: Area of space-time with a gravitational field so intense that its escape velocity is equal to or exceeds the speed of light. [e]
• Comet: Add brief definition or description
•  Dark matter: Theoretical matter that neither emits nor absorbs light and appears to interact with other matter only gravitationally. [e] -- Thomas Simmons
• HR Diagram: Add brief definition or description
•  IAU: Internationally recognized authority for assigning designations to celestial bodies (stars, planets, asteroids, etc), headquartered in Paris, France. [e]
•  Kepler's laws: Three mathematical laws were discovered by German mathematician and astronomer Johannes Kepler (1571–1630), and used by him to describe the motion of planets in the Solar System, and the motion of any two bodies orbiting each other. [e]
• Neutron star: Add brief definition or description
•  Nicolaus Copernicus: (1473–1543) Astronomer, founder of the heliocentric system. [e]
• Supernova: A catastrophic explosion of a star about five times the size of the sun, which occurs when the star collapses; either a neutron star or a black hole is formed as a result. [e]
• William Herschel: Add brief definition or description
•  Mercury: The first planet from the Sun in our solar system; named after the Roman messenger of gods. [e] -- Thomas Simmons
•  Jupiter: The fifth planet from the Sun in our solar system; named after the Roman god of the same name; largest planet in our solar system. [e] -- Thomas Simmons
•  Uranus: The seventh planet from the Sun in our solar system; name after the Greek god of the sky. [e] -- Thomas Simmons
•  Neptune: The eighth planet from the Sun in our solar system; named after the Roman god of the sea. [e] -- Thomas Simmons
•  Dwarf planet: A celestial object orbiting a sun that is massive enough to obtain a round shape but too small to clear its orbital path of other celestial bodies. [e] -- Thomas Simmons
•  Pluto: A dwarf planet above Neptune that, for many years, have been considered a planet. Named after the Roman god of the underworld. [e]
• Asteroid: Add brief definition or description
• Asteroid belt: Add brief definition or description
• Binary star: Add brief definition or description
• Celestial coordinates: Any of a number of reference systems designed to specify the positions of celestial objects. [e]
• Celestial mechanics: Study of the application of the laws of physics to the motions of planets, satellites, and other celestial objects. [e]
• Cepheid variable: Pulsating variable star which exhibits a relation between period of variation and absolute luminosity as a result of which they are good indicators of cosmic distances. [e]
•  Ceres (dwarf planet): The most massive body in the asteroid belt. Originally classified as a planet, it later became the number one asteroid; now a dwarf planet. [e]
• Cosmic microwave background: Add brief definition or description
• Cosmic rays: Add brief definition or description
•  Crab Nebula: An emission nebula located in the constellation Taurus. [e]
• Eros (asteroid): Add brief definition or description
• Flare star: Add brief definition or description
• Galilean satellites: Add brief definition or description
•  Globular cluster: Spherical, globular collection of stars that orbits a galactic core as a satellite, and is generally smaller in size than a galaxy. [e]
• H I region: Add brief definition or description
• H II region: Add brief definition or description
• Halley's comet: Add brief definition or description
• Hubble constant: Add brief definition or description
• Magellanic Clouds: Add brief definition or description
• Nebula: Add brief definition or description
• Nova: Add brief definition or description
•  Olber's paradox: Argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. [e]
•  Open cluster: Any group of young stars held together by gravity [e]
• Orion nebula: Add brief definition or description
• 2006 definition of planet: Add brief definition or description
•  Kuiper belt: Region of the Solar System extending from the orbit of Neptune (at 30 AU) to approximately 55 AU from the Sun, containing thousands of icy bodies, some of which are on highly elliptical orbits, periodically visiting the inner solar system as comets. [e] -- Thomas Simmons
• Extrasolar Planet: Add brief definition or description
• Scattered disc: Add brief definition or description
• Meteroid: Add brief definition or description
• Dust: Add brief definition or description
• Oort Cloud: Add brief definition or description
• Walter Baade: Add brief definition or description
• Friedrich Bessel: Add brief definition or description
•  Parsec: Unit of astronomical length based on the distance from Earth at which stellar parallax is one second of arc and equal to 3.258 light-years, 3.086 × 1013 kilometers, or 1.918 × 1013 miles. [e] -- Anthony Argyriou
• Planetary nebula: Add brief definition or description
• Pleiades: Add brief definition or description
•  Precession: The motion of the axis of a spinning body, such as the wobble of a spinning top, when there is an external force acting on the axis. [e]
• Proper motion: Add brief definition or description
• Pulsar: Add brief definition or description
• Quasar: Add brief definition or description
•  Redshift: A term used in Astronomy and Physics to refer to the phenomenon by which electromagnetic radiation's observed wavelength increases, thereby causing an apparent decrease in the observed frequency. [e]
• Solar eclipse: Add brief definition or description
• Solar wind: Add brief definition or description
• Star formation: Add brief definition or description
• Stellar evolution: Add brief definition or description
• Stellar parallax: Add brief definition or description
• Stellar populations: Add brief definition or description
• Sunspots: Add brief definition or description
•  Tide: The rising or falling of an ocean due to tidal forces. [e] (also in Earth Sciences)
•  Variable star: A star whose apparent brightness exhibits periodic variations [e]
• White dwarf: Add brief definition or description
• Henrietta Leavitt: (1868-1921) American astronomer, discoverer of thousands of variable stars whose studies of Cepheid variables led to the discovery of the period-luminosity relationship. [e]
•  Isaac Newton: (1642–1727) English physicist and mathematician, best known for his elucidation of the universal theory of gravitation and his development of calculus. [e]
• Edward C. Pickering: Add brief definition or description
• Henry Norris Russell: (1877-1957) American astronomer who first developed the Hertzsprung-Russell diagram relating the absolute magnitudes of main sequence stars with their spectral types. [e]
• Harlow Shapley: (1885-1972) American astronomer whose studies of globular clusters enabled him to derive the first scientific estimates of the size and extent of the Milky Way Galaxy. [e]
• European Space Agency: Add brief definition or description
• Royal Astronomical Society: British organization for professional astronomers, founded in 1820; publishes the Monthly Notices (MNRAS). [e]
• Palomar Observatory: Add brief definition or description
• Annie Jump Cannon: Add brief definition or description
• Alvan Clark: Add brief definition or description
• George Ellery Hale: Add brief definition or description
• Edwin Hubble: (1889-1953) American astronomer who demonstrated the existence of galaxies external to the Milky Way Galaxy and a relation between distance and velocity of recession for galaxies. [e]
•  Jacobus Kapteyn: same as Jacobus Kapteijn; Dutch astronomer (1851 - 1922). [e]
• Gerard Kuiper: Add brief definition or description
•  Spectroscopy: The study of a system or object by means of selected frequency bands in the electromagnetic spectrum. [e]

Already-written core articles in this workgroup

•  Sun: The star that defines our solar system. [e]
•  Constellation: An officially recognised formation of stars, such as the Big Dipper or Orion. [e]
•  Tycho Brahe: Danish astronomer of the 16th century. [e]
•  Venus: The second planet from the Sun in our solar system; named after the Roman goddess of love. [e]
•  Mars: The fourth planet from the Sun in our solar system; named after the Roman god of war; also known as the "Red Planet". [e]
•  Saturn: The sixth planet from the Sun in our solar system; named after the Roman god of agriculture and harvest. [e]
•  Calendar: A method used for keeping time on a scale of years. [e]
•  Galaxy: Gravitationally bound system of stars typically contain ten million to one trillion stars. [e]
•  Galileo Galilei: (1564-1642) Italian scientist, a pioneer in combining mathematical theory with systematic experiment in science, who came into conflict with the Church. [e]
•  NASA: Independent agency of the U.S. government responsible for the nation's public space program. [e]