Matches in DBpedia 2016-04 for { <http://dbpedia.org/resource/Main_sequence> ?p ?o }
- Main_sequence abstract "In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or \"dwarf\" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.".
- Main_sequence thumbnail Sun920607.jpg?width=300.
- Main_sequence wikiPageID "19605".
- Main_sequence wikiPageLength "54655".
- Main_sequence wikiPageOutDegree "180".
- Main_sequence wikiPageRevisionID "707487117".
- Main_sequence wikiPageWikiLink 61_Cygni.
- Main_sequence wikiPageWikiLink 70_Ophiuchi.
- Main_sequence wikiPageWikiLink Absolute_magnitude.
- Main_sequence wikiPageWikiLink Alpha_Coronae_Borealis.
- Main_sequence wikiPageWikiLink Alpha_Mensae.
- Main_sequence wikiPageWikiLink Annie_Jump_Cannon.
- Main_sequence wikiPageWikiLink Apparent_magnitude.
- Main_sequence wikiPageWikiLink Astronomy.
- Main_sequence wikiPageWikiLink Bengt_Strömgren.
- Main_sequence wikiPageWikiLink Beta_Cephei_variable.
- Main_sequence wikiPageWikiLink Beta_Comae_Berenices.
- Main_sequence wikiPageWikiLink Beta_Pictoris.
- Main_sequence wikiPageWikiLink Binary_star.
- Main_sequence wikiPageWikiLink Black_body.
- Main_sequence wikiPageWikiLink Black_hole.
- Main_sequence wikiPageWikiLink Brown_dwarf.
- Main_sequence wikiPageWikiLink CNO_cycle.
- Main_sequence wikiPageWikiLink Cambridge.
- Main_sequence wikiPageWikiLink Carbon.
- Main_sequence wikiPageWikiLink Category:Hertzsprung–Russell_classifications.
- Main_sequence wikiPageWikiLink Category:Main-sequence_stars.
- Main_sequence wikiPageWikiLink Category:Star_types.
- Main_sequence wikiPageWikiLink Category:Stellar_evolution.
- Main_sequence wikiPageWikiLink Cepheid_variable.
- Main_sequence wikiPageWikiLink Chicago.
- Main_sequence wikiPageWikiLink Color_index.
- Main_sequence wikiPageWikiLink Convection.
- Main_sequence wikiPageWikiLink Convection_zone.
- Main_sequence wikiPageWikiLink Curve.
- Main_sequence wikiPageWikiLink Delta_Scuti_variable.
- Main_sequence wikiPageWikiLink EZ_Aquarii.
- Main_sequence wikiPageWikiLink Earth.
- Main_sequence wikiPageWikiLink Edward_Charles_Pickering.
- Main_sequence wikiPageWikiLink Effective_temperature.
- Main_sequence wikiPageWikiLink Ejnar_Hertzsprung.
- Main_sequence wikiPageWikiLink Electron_degeneracy_pressure.
- Main_sequence wikiPageWikiLink Electron_scattering.
- Main_sequence wikiPageWikiLink Eta_Arietis.
- Main_sequence wikiPageWikiLink Exothermic_process.
- Main_sequence wikiPageWikiLink G-type_main-sequence_star.
- Main_sequence wikiPageWikiLink Gamma_Virginis.
- Main_sequence wikiPageWikiLink Gravitational_collapse.
- Main_sequence wikiPageWikiLink HD_32450.
- Main_sequence wikiPageWikiLink Harvard_College_Observatory.
- Main_sequence wikiPageWikiLink Helium.
- Main_sequence wikiPageWikiLink Henry_Norris_Russell.
- Main_sequence wikiPageWikiLink Hertzsprung–Russell_diagram.
- Main_sequence wikiPageWikiLink Hydrogen.
- Main_sequence wikiPageWikiLink Hydrostatic_equilibrium.
- Main_sequence wikiPageWikiLink Initial_mass_function.
- Main_sequence wikiPageWikiLink Instability_strip.
- Main_sequence wikiPageWikiLink Interstellar_medium.
- Main_sequence wikiPageWikiLink Jeans_instability.
- Main_sequence wikiPageWikiLink Jupiter.
- Main_sequence wikiPageWikiLink K-type_main-sequence_star.
- Main_sequence wikiPageWikiLink Kelvin.
- Main_sequence wikiPageWikiLink Luminosity.
- Main_sequence wikiPageWikiLink Mass.
- Main_sequence wikiPageWikiLink Mass–luminosity_relation.
- Main_sequence wikiPageWikiLink Metallicity.
- Main_sequence wikiPageWikiLink Mnemonic.
- Main_sequence wikiPageWikiLink Molecular_cloud.
- Main_sequence wikiPageWikiLink New_York.
- Main_sequence wikiPageWikiLink Nitrogen.
- Main_sequence wikiPageWikiLink Nuclear_fusion.
- Main_sequence wikiPageWikiLink Opacity_(optics).
- Main_sequence wikiPageWikiLink Order_of_approximation.
- Main_sequence wikiPageWikiLink Order_of_magnitude.
- Main_sequence wikiPageWikiLink Oxygen.
- Main_sequence wikiPageWikiLink Parallax.
- Main_sequence wikiPageWikiLink Phi_Orionis.
- Main_sequence wikiPageWikiLink Photosphere.
- Main_sequence wikiPageWikiLink Pi_Andromedae.
- Main_sequence wikiPageWikiLink Plasma_(physics).
- Main_sequence wikiPageWikiLink Potsdam.
- Main_sequence wikiPageWikiLink Power_law.
- Main_sequence wikiPageWikiLink Pre-main-sequence_star.
- Main_sequence wikiPageWikiLink Princeton_University.
- Main_sequence wikiPageWikiLink Princeton_University_Press.
- Main_sequence wikiPageWikiLink Proton–proton_chain_reaction.
- Main_sequence wikiPageWikiLink Protostar.
- Main_sequence wikiPageWikiLink Quantum_mechanics.
- Main_sequence wikiPageWikiLink Radiation.
- Main_sequence wikiPageWikiLink Radiation_zone.
- Main_sequence wikiPageWikiLink Radius.
- Main_sequence wikiPageWikiLink Red_dwarf.
- Main_sequence wikiPageWikiLink Red_giant.
- Main_sequence wikiPageWikiLink Sirius.
- Main_sequence wikiPageWikiLink Solar_luminosity.
- Main_sequence wikiPageWikiLink Solar_mass.
- Main_sequence wikiPageWikiLink Spectral_line.
- Main_sequence wikiPageWikiLink Spectrum.
- Main_sequence wikiPageWikiLink Star.
- Main_sequence wikiPageWikiLink Star_cluster.