{"@context":{"ns0":"http://astrothesaurus.org/uat/","rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","owl":"http://www.w3.org/2002/07/owl#","skos":"http://www.w3.org/2004/02/skos/core#","dct":"http://purl.org/dc/terms/","ns1":"http://editor.vocabs.ands.org.au/user/","metadata_def":"http://data.bioontology.org/metadata/def/"},"@graph":[{"@id":"ns0:1137","@type":["owl:NamedIndividual","skos:Concept"],"dct:modified":[{"@type":"http://www.w3.org/2001/XMLSchema#dateTime","@value":"2020-11-03T19:46:55.553Z"},{"@type":"http://www.w3.org/2001/XMLSchema#dateTime","@value":"2020-11-03T19:47:07.379Z"}],"skos:prefLabel":{"@language":"en","@value":"O stars"},"skos:definition":{"@language":"en","@value":"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:altLabel":[{"@language":"en","@value":"Class O stars"},{"@language":"en","@value":"O-type stars"}],"dct:contributor":{"@id":"ns1:AAS_Frey.Katie_Admin"},"metadata_def:mappingLoom":"ostars","metadata_def:mappingSameURI":{"@id":"ns0:1137"},"skos:broader":[{"@id":"ns0:2051"},{"@id":"ns0:430"}],"skos:narrower":[{"@id":"ns0:1132"},{"@id":"ns0:1135"},{"@id":"ns0:1136"},{"@id":"ns0:1138"},{"@id":"ns0:1139"},{"@id":"ns0:1153"},{"@id":"ns0:1154"},{"@id":"ns0:1155"}],"skos:related":{"@id":"ns0:1589"}},{"@id":"ns0:2051","skos:narrower":{"@id":"ns0:1137"}},{"@id":"ns0:430","skos:narrower":{"@id":"ns0:1137"}},{"@id":"ns0:1132","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1135","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1136","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1138","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1139","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1153","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1154","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1155","skos:broader":{"@id":"ns0:1137"}},{"@id":"ns0:1589","skos:related":{"@id":"ns0:1137"}}]}