| gptkbp:instanceOf | gptkb:star gptkb:binary_star_system
 
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                                | gptkbp:apparentMagnitude | 8.95 
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                                | gptkbp:catalogueNumber | gptkb:4U_1956+35 gptkb:BD+34_3815
 gptkb:HIP_98298
 gptkb:SAO_69181
 gptkb:HDE_226868
 gptkb:V1357_Cygni
 
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                                | gptkbp:component | gptkb:black_hole gptkb:red_supergiant
 
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                                | gptkbp:constellation | gptkb:Cygnus 
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                                | gptkbp:declination | +35° 12′ 05.78″ 
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                                | gptkbp:discoveredIn | 1964 
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                                | gptkbp:distanceFromEarth | ~7,200 light-years 
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                                | gptkbp:hasCompanion | gptkb:black_hole gptkb:red_supergiant
 
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                                | gptkbp:locatedIn | gptkb:Milky_Way 
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                                | gptkbp:massOfBlackHole | ~21 solar masses 
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                                | gptkbp:massOfCompanionStar | ~19 solar masses 
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                                | gptkbp:notableFor | first widely accepted black hole candidate 
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                                | gptkbp:orbitType | 5.6 days 
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                                | gptkbp:otherName | gptkb:Cygnus_X-1 
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                                | gptkbp:parallax | 0.5111 mas 
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                                | gptkbp:properMotionRA | -3.78 mas/yr -6.40 mas/yr
 
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                                | gptkbp:radialVelocity | -5.4 km/s 
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                                | gptkbp:rightAscension | 19h 58m 21.675s 
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                                | gptkbp:spectralType | gptkb:O9.7_Iab 
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                                | gptkbp:variableType | gptkb:binary_star_system 
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                                | gptkbp:XRaySource | yes 
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                                | gptkbp:bfsParent | gptkb:V1357_Cygni 
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                                | gptkbp:bfsLayer | 7 
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                                | https://www.w3.org/2000/01/rdf-schema#label | V1357 Cyg 
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