The following outline is provided as an overview of and topical guide to astronomy:
Astronomy – studies the universe beyond Earth, including its formation and development, and the evolution, physics, chemistry, meteorology, and motion of celestial objects (such as galaxies, planets, etc.) and phenomena that originate outside the atmosphere of Earth (such as the cosmic background radiation). Astronomy also intersects with biology, as astrobiology, studying potential life throughout the universe.
Nature of astronomy Astronomy can be described as all the following:
An academic discipline: one with academic departments, curricula and degrees; national and international societies; and specialized journals. A scientific field (a branch of science) – widely recognized category of specialized expertise within science, and typically embodies it A natural science – one that seeks to elucidate the rules that govern the natural world using empirical and scientific methods. A branch or field of space science A hobby or part-time pursuit for the satisfaction of personal curiosity or appreciation of beauty, the latter especially including astrophotography.
Branches Astrobiology – studies the advent and evolution of biological systems in the universe. Astrophysics (outline) – branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior. Among the objects studied are galaxies, stars, planets, exoplanets, the interstellar medium and the cosmic microwave background; and the properties examined include luminosity, density, temperature, and chemical composition. The subdisciplines of theoretical astrophysics are: Compact objects – this subdiscipline studies very dense matter in white dwarfs and neutron stars and their effects on environments including accretion. Physical cosmology – origin and evolution of the universe as a whole. The study of cosmology is theoretical astrophysics at its largest scale. Quantum cosmology - the study of cosmology through the use of quantum field theory to explain phenomena general relativity cannot due to limitations in its framework. Computational astrophysics – The study of astrophysics using computational methods and tools to develop computational models. Galactic astronomy – deals with the structure and components of our Galaxy and of other galaxies. High energy astrophysics – studies phenomena occurring at high energies including active galactic nuclei, supernovae, gamma-ray bursts, quasars, and shocks. Interstellar astrophysics – study of the interstellar medium, intergalactic medium and dust. Extragalactic astronomy – study of objects (mainly galaxies) outside our Galaxy, including galaxy formation and evolution. Stellar astronomy – concerned with Star formation, physical properties, main sequence life span, variability, stellar evolution and extinction. Plasma astrophysics – studies properties of plasma in outer space. Relativistic astrophysics – studies effects of special relativity and general relativity in astrophysical contexts including gravitational waves, gravitational lensing and black holes. Solar physics – Sun and its interaction with the remainder of the Solar System and interstellar space. Planetary Science – study of planets, moons, and planetary systems. Atmospheric science – study of atmospheres and weather. Exoplanetology – various planets outside of the Solar System Planetary formation – formation of planets and moons in the context of the formation and evolution of the Solar System. Planetary rings – dynamics, stability, and composition of planetary rings Magnetospheres – magnetic fields of planets and moons Planetary surfaces – surface geology of planets and moons Planetary interiors – interior composition of planets and moons Small Solar System bodies – smallest bodies, including asteroids, comets, Kuiper belt objects, and dust. Astronomy divided by general technique used for astronomical research: Astrometry – study of the position of objects in the sky and their changes of position. Defines the system of coordinates used and the kinematics of objects in our Galaxy. Observational astronomy – practice of observing celestial objects by using telescopes and other astronomical apparatus. It is concerned with recording data. The subdisciplines of observational astronomy are generally made by the specifications of the detectors, specifically the ranges of wavelengths observed: Radio astronomy – Above 300 μm Submillimetre astronomy – 200 μm to 1 mm Infrared astronomy – 0.7–350 μm Optical astronomy – 380–750 nm Ultraviolet astronomy – 10–320 nm X-ray astronomy – 0.01–10 nm Gamma-ray astronomy – Below 0.01 nm Cosmic ray astronomy – Cosmic rays, including plasma Neutrino astronomy – Neutrinos Dust astronomy – Cosmic dust Gravitational wave astronomy – Gravitons Photometry – study of how bright celestial objects are when passed through different filters Spectroscopy – study of the spectra of astronomical objects Other disciplines that may be considered part of astronomy: Archaeoastronomy Astrochemistry
History
History of astronomy History of the Center of the Universe Geocentric model Heliocentrism Copernican heliocentrism Tychonic system Archaeoastronomy Archaeoastronomy and Vedic chronology Pretelescopic astronomy Babylonian astronomy Chinese astronomy Egyptian astronomy Greek astronomy Hebrew astronomy Indian astronomy Islamic astronomy Russian astronomy Astronomy in the Middle Ages Science in Medieval Western Europe Astronomy in medieval Islam History of astronomy in the Renaissance Scientific developments during the Scientific Revolution Patronage in astronomy Copernican Revolution Copernican heliocentrism Nicolaus Copernicus On the Revolutions of the Heavenly Spheres Tycho Brahe Tychonic system Galileo Galilei Dialogue Concerning the Two Chief World Systems defense of the heliocentric system written by Galileo, which led to his trial and house arrest by the Inquisition. Invention of the telescope History of visible-light astronomy History of astronomy in the Age of Reflection
History of X-ray astronomy History of infrared astronomy History of gamma-ray astronomy History of supernova observation List of supernovae
Basic astronomical phenomena
Atmosphere Celestial pole Eclipse Ecliptic Cosmic rays Kepler's laws Doppler effect Nutation Occultation Orbit Perturbation Precession Proper motion Redshift Solar eclipse Tides Zodiac
Astronomical objects Astronomical object
Solar System
Solar System Geology of solar terrestrial planets List of Solar System objects List of Solar System objects by size Galilean satellites Halley's Comet
Sun
Sun Location Milky Way Solar System Stellar classification
Internal structure Standard Solar Model Solar core Radiation zone Convection zone Stellar atmosphere Photosphere Supergranulation Granule Facula Sunspot Chromosphere Plage Spicule Moreton wave Solar corona Solar transition region Coronal hole Coronal loop Coronal mass ejection Solar prominence Helmet streamer Solar variation Solar cycle List of solar cycles Solar maximum Solar minimum Wolf number Solar flare Helioseismology Heliosphere Solar wind Heliospheric current sheet
Heliopause Bow shock Related phenomena Solar dynamo Solar eclipse Sunlight Solar energy Equipment used to study the Sun Solar telescope
Planets
Planet Features Natural satellites (moons) Planetary rings Planets of the Solar System Mercury Venus Earth Moon Mars Moons of Mars Jupiter Moons of Jupiter Rings of Jupiter Saturn Moons of Saturn Rings of Saturn Uranus Moons of Uranus Rings of Uranus Neptune Moons of Neptune Rings of Neptune Dwarf planets of the Solar System Ceres Pluto Moons of Pluto Haumea Moons of Haumea Makemake Eris Dysnomia
Small Solar System bodies
Small Solar System body Asteroids Minor planets :Category:Asteroid groups and families Vulcanoid asteroids Near-Earth asteroids Asteroid belt Trojan asteroid Centaur Neptune Trojans Minor planet moons Meteoroids 2 Pallas 3 Juno 4 Vesta 10 Hygiea List of asteroids Meanings of asteroid names Trans-Neptunian objects Kuiper belt Plutinos 90482 Orcus Cubewanos 15760 Albion Haumea family 50000 Quaoar Scattered disc 225088 Gonggong 90377 Sedna Comets List of periodic comets List of non-periodic comets Damocloids Hills cloud Oort cloud
Exoplanets Exoplanet (also known as extrasolar planets) – planet outside the Solar System. A total of 4,341 such planets have been identified as of 28 Jan 2021. Super-Earth – exoplanet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants. Mini-Neptune – also known as a gas dwarf or transitional planet. A planet up to 10 Earth masses, but less massive than Uranus and Neptune. Super-Jupiter – an exoplanet more massive than Jupiter. Sub-Earth – an exoplanet "substantially less massive" than Earth and Venus. Circumbinary planet – an exoplanet that orbits two stars. Hot Jupiter – an exoplanet whose characteristics are similar to Jupiter, but that have high surface temperatures because they orbit very close to their parent stars, whereas Jupiter orbits its parent star (the Sun) at 5.2 AU (780×106 km), causing low surface temperatures. Hot Neptune – an exoplanet in an orbit close to its star (normally less than one astronomical unit away), with a mass similar to that of Uranus or Neptune. Pulsar planet – a planet that orbits a pulsar or a rapidly rotating neutron star. Rogue planet (also known as an interstellar planet) – a planetary-mass object that orbits the galaxy directly.
Stars and stellar objects
Compact object Fixed stars
Stars
Stellar evolution Star formation Pre–main sequence Main sequence Horizontal branch Asymptotic giant branch Dredge-up Instability strip Red clump PG 1159 star Mira variable Planetary nebula Protoplanetary nebula Luminous red nova Luminous blue variable Wolf–Rayet star Supernova impostor Supernova Hypernova Hertzsprung–Russell diagram Color–color diagram Protostars Molecular cloud H II region Bok globule Young stellar object Herbig–Haro object Hayashi track Hayashi limit Henyey track Orion variable T Tauri star FU Orionis star Herbig Ae/Be Luminosity class Subdwarf star Dwarf star Blue dwarf Red dwarf Subgiant Giant star Blue giant Red giant Bright giant Supergiant Blue supergiant Red supergiant Yellow supergiant Hypergiant Yellow hypergiant Blue straggler Stellar classification O-type main-sequence star B-type main-sequence star A-type main-sequence star F-type main-sequence star G-type main-sequence star K-type main-sequence star M-type main-sequence star Be star OB star Subdwarf B star Late-type star Peculiar star Am star Ap and Bp stars Rapidly oscillating Ap star Barium star Carbon star CH star Extreme helium star Lambda Boötis star Lead star Mercury-manganese star S-type star Shell star Technetium star Remnants White dwarf Black dwarf Helium planet Neutron star Pulsar Magnetar Stellar black hole Compact star Quark star Exotic star Stellar core: EF Eridani Failed and theoretical stars Substellar object Brown dwarf Sub-brown dwarf Planetar Boson star Dark star Quasistar Thorne–Żytkow object Iron star Stellar nucleosynthesis Alpha process Triple-alpha process Proton–proton chain reaction Helium flash CNO cycle Lithium burning Carbon-burning process Neon-burning process Oxygen-burning process Silicon-burning process S-process R-process Nova Nova remnant Stellar structure Solar core Convection zone Microturbulence Solar-like oscillations Radiation zone Photosphere Starspot Chromosphere Stellar corona Stellar wind Stellar-wind bubble