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Matches in DBpedia 2016-04 for { <http://dbpedia.org/resource/Pre-main-sequence_star> ?p ?o }

• Pre-main-sequence_star abstract "A pre-main-sequence star (also known as a PMS star and PMS object) is a star in the stage when it has not yet reached the main sequence. Earlier in its life, the object is a protostar that grows by acquiring mass from its surrounding envelope of interstellar dust and gas. After the protostar blows away this envelope, it is optically visible, and appears on the stellar birthline in the Hertzsprung-Russell diagram. At this point, the star has acquired nearly all of its mass but has not yet started hydrogen burning (i.e. nuclear fusion of hydrogen). The star then contracts, its internal temperature rising until it begins hydrogen burning on the zero age main sequence. This period of contraction is the pre-main sequence stage. An observed PMS object can either be a T Tauri star, if it has fewer than 2 solar masses (M☉), or else a Herbig Ae/Be star, if it has 2 to 8 M☉. Yet more massive stars have no pre-main-sequence stage because they contract too quickly as protostars. By the time they become visible, the hydrogen in their centers is already fusing and they are main-sequence objects.The energy source of PMS objects is gravitational contraction, as opposed to hydrogen burning in main-sequence stars. In the Hertzsprung–Russell diagram, pre-main-sequence stars with more than 0.5 M☉ first move vertically downward along Hayashi tracks, then leftward and horizontally along Henyey tracks, until they finally halt at the main sequence. Pre-main-sequence stars with less than 0.5 M☉ contract vertically along the Hayashi track for their entire evolution.PMS stars can be differentiated empirically from main-sequence stars by using stellar spectra to measure their surface gravity. A PMS object has a larger radius than a main-sequence star with the same stellar mass and thus has a lower surface gravity. Although they are optically visible, PMS objects are rare relative to those on the main sequence, because their contraction lasts for only 1 percent of the time required for hydrogen fusion. During the early portion of the PMS stage, most stars have circumstellar disks, which are the sites of planet formation.".
• Pre-main-sequence_star wikiPageID "5557857".
• Pre-main-sequence_star wikiPageLength "3731".
• Pre-main-sequence_star wikiPageOutDegree "34".
• Pre-main-sequence_star wikiPageRevisionID "698454345".
• Pre-main-sequence_star wikiPageWikiLink Category:Hertzsprung–Russell_classifications.
• Pre-main-sequence_star wikiPageWikiLink Category:Pre-main-sequence_stars.
• Pre-main-sequence_star wikiPageWikiLink Category:Star_formation.
• Pre-main-sequence_star wikiPageWikiLink Category:Star_types.
• Pre-main-sequence_star wikiPageWikiLink Circumstellar_disc.
• Pre-main-sequence_star wikiPageWikiLink Hayashi_track.
• Pre-main-sequence_star wikiPageWikiLink Henyey_track.
• Pre-main-sequence_star wikiPageWikiLink Be_star.
• Pre-main-sequence_star wikiPageWikiLink Hertzsprung–Russell_diagram.
• Pre-main-sequence_star wikiPageWikiLink Kelvin–Helmholtz_mechanism.
• Pre-main-sequence_star wikiPageWikiLink Main_sequence.
• Pre-main-sequence_star wikiPageWikiLink Nebular_hypothesis.
• Pre-main-sequence_star wikiPageWikiLink Nuclear_fusion.
• Pre-main-sequence_star wikiPageWikiLink Proton–proton_chain_reaction.
• Pre-main-sequence_star wikiPageWikiLink Protoplanetary_disk.
• Pre-main-sequence_star wikiPageWikiLink Protostar.
• Pre-main-sequence_star wikiPageWikiLink Solar_mass.
• Pre-main-sequence_star wikiPageWikiLink Star.
• Pre-main-sequence_star wikiPageWikiLink Stellar_birthline.
• Pre-main-sequence_star wikiPageWikiLink Stellar_evolution.
• Pre-main-sequence_star wikiPageWikiLink Stellar_mass.
• Pre-main-sequence_star wikiPageWikiLink Stellar_nucleosynthesis.
• Pre-main-sequence_star wikiPageWikiLink T_Tauri_star.
• Pre-main-sequence_star wikiPageWikiLink Young_stellar_object.
• Pre-main-sequence_star wikiPageWikiLinkText "Pre-Main-Sequence star".
• Pre-main-sequence_star wikiPageWikiLinkText "Pre-main-sequence star".
• Pre-main-sequence_star wikiPageWikiLinkText "Pre-main-sequence".
• Pre-main-sequence_star wikiPageWikiLinkText "Pre–main sequence".
• Pre-main-sequence_star wikiPageWikiLinkText "pre main sequence star".
• Pre-main-sequence_star wikiPageWikiLinkText "pre-main sequence".
• Pre-main-sequence_star wikiPageWikiLinkText "pre-main-sequence phase".
• Pre-main-sequence_star wikiPageWikiLinkText "pre-main-sequence star".
• Pre-main-sequence_star wikiPageWikiLinkText "pre-main-sequence".
• Pre-main-sequence_star wikiPageUsesTemplate Template:Astronomy-stub.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Portal.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Refimprove.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Reflist.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Solar_mass.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Star.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Star-stub.
• Pre-main-sequence_star wikiPageUsesTemplate Template:Star_formation.
• Pre-main-sequence_star subject Category:Hertzsprung–Russell_classifications.
• Pre-main-sequence_star subject Category:Pre-main-sequence_stars.
• Pre-main-sequence_star subject Category:Star_formation.
• Pre-main-sequence_star subject Category:Star_types.
• Pre-main-sequence_star hypernym Star.
• Pre-main-sequence_star type CelestialBody.
• Pre-main-sequence_star type Place.
• Pre-main-sequence_star type Star.
• Pre-main-sequence_star type Location.
• Pre-main-sequence_star type Place.
• Pre-main-sequence_star type Thing.
• Pre-main-sequence_star type Concept.
• Pre-main-sequence_star comment "A pre-main-sequence star (also known as a PMS star and PMS object) is a star in the stage when it has not yet reached the main sequence. Earlier in its life, the object is a protostar that grows by acquiring mass from its surrounding envelope of interstellar dust and gas. After the protostar blows away this envelope, it is optically visible, and appears on the stellar birthline in the Hertzsprung-Russell diagram.".
• Pre-main-sequence_star label "Pre-main-sequence star".
• Pre-main-sequence_star sameAs Q1062509.
• Pre-main-sequence_star sameAs Estrella_pre-seqüència_principal.
• Pre-main-sequence_star sameAs Hvězda_před_hlavní_posloupností.
• Pre-main-sequence_star sameAs Estrella_presecuencia_principal.
• Pre-main-sequence_star sameAs Sekuentzia_nagusiko_aurreko_izar.
• Pre-main-sequence_star sameAs Étoile_de_la_pré-séquence_principale.
• Pre-main-sequence_star sameAs मुख्य_अनुक्रम_पूर्वी_तारा.
• Pre-main-sequence_star sameAs Stella_pre-sequenza_principale.
• Pre-main-sequence_star sameAs 前主系列星.
• Pre-main-sequence_star sameAs მთავარ_მიმდევრობამდელი_ვარსკვლავი.
• Pre-main-sequence_star sameAs 전주계열성.
• Pre-main-sequence_star sameAs Estrela_pré-sequência_principal.
• Pre-main-sequence_star sameAs m.0dsg6f.
• Pre-main-sequence_star sameAs Stea_pre-secvența_principală.
• Pre-main-sequence_star sameAs Звёзды_до_главной_последовательности.
• Pre-main-sequence_star sameAs Hviezda_pred_hlavnou_postupnosťou.
• Pre-main-sequence_star sameAs ดาวฤกษ์ก่อนแถบลำดับหลัก.
• Pre-main-sequence_star sameAs Anakol_öncesi_yıldız.
• Pre-main-sequence_star sameAs Зоря_до_головної_послідовності.
• Pre-main-sequence_star sameAs Q1062509.
• Pre-main-sequence_star sameAs 主序前星.
• Pre-main-sequence_star wasDerivedFrom Pre-main-sequence_star?oldid=698454345.
• Pre-main-sequence_star isPrimaryTopicOf Pre-main-sequence_star.