<?xml version="1.0" encoding="UTF-8"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:ns0="http://astrothesaurus.org/uat/" xmlns:owl="http://www.w3.org/2002/07/owl#" xmlns:skos="http://www.w3.org/2004/02/skos/core#" xmlns:dct="http://purl.org/dc/terms/" xmlns:ns1="http://editor.vocabs.ands.org.au/user/" xmlns:metadata_def="http://data.bioontology.org/metadata/def/"> <owl:NamedIndividual rdf:about="http://astrothesaurus.org/uat/1137"> <rdf:type rdf:resource="http://www.w3.org/2004/02/skos/core#Concept"/> <dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2020-11-03T19:46:55.553Z</dct:modified> <dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2020-11-03T19:47:07.379Z</dct:modified> <skos:prefLabel xml:lang="en">O stars</skos:prefLabel> <skos:definition xml:lang="en">A luminous, hot, blue star whose spectrum is dominated by the lines of hydrogen, atomic helium, and ionized helium; also known as O-type star. This is the earliest spectral type and the only main sequence star in which ionized helium is present. The effective temperatures of these stars range from about 30,000 K to 50,000 K, their luminosities from 50,000 to 1,000,000 times that of solar luminosity, and their masses from about 20 to 100 solar masses. The hottest O-type stars display high ionization emission features such as N III and He II, Of star. They are divided into subtypes O2, the hottest, to O9.7, the coldest. O-type stars are relatively rare, for each star of 100 solar masses there are 10^6 stars of solar mass. They are relatively short-lived since they spend only a few million years on the main sequence. The brightest O-type star in the sky visible with naked eye is Alnitak.</skos:definition> <skos:altLabel xml:lang="en">Class O stars</skos:altLabel> <skos:altLabel xml:lang="en">O-type stars</skos:altLabel> <dct:contributor rdf:resource="http://editor.vocabs.ands.org.au/user/AAS_Frey.Katie_Admin"/> <metadata_def:mappingLoom>ostars</metadata_def:mappingLoom> <metadata_def:mappingSameURI rdf:resource="http://astrothesaurus.org/uat/1137"/> <skos:broader rdf:resource="http://astrothesaurus.org/uat/2051"/> <skos:broader rdf:resource="http://astrothesaurus.org/uat/430"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1132"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1135"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1136"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1138"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1139"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1153"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1154"/> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1155"/> <skos:related rdf:resource="http://astrothesaurus.org/uat/1589"/> </owl:NamedIndividual> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1132"> <skos:broader> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1137"> <metadata_def:mappingSameURI rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> </skos:broader> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1135"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1136"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1138"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1139"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1153"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1154"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1155"> <skos:broader rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/1589"> <skos:related rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/2051"> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> <rdf:Description rdf:about="http://astrothesaurus.org/uat/430"> <skos:narrower rdf:resource="http://astrothesaurus.org/uat/1137"/> </rdf:Description> </rdf:RDF>