|
gptkbp:instanceOf
|
gptkb:star
binary star system
|
|
gptkbp:apparentMagnitude
|
8.95
|
|
gptkbp:catalogueNumber
|
gptkb:4U_1956+35
gptkb:BD+34_3815
gptkb:HIP_98298
gptkb:SAO_69181
gptkb:HDE_226868
gptkb:V1357_Cygni
|
|
gptkbp:component
|
black hole
red supergiant
|
|
gptkbp:constellation
|
gptkb:Cygnus
|
|
gptkbp:declination
|
+35° 12′ 05.78″
|
|
gptkbp:discoveredIn
|
1964
|
|
gptkbp:distanceFromEarth
|
~7,200 light-years
|
|
gptkbp:hasCompanion
|
black hole
red supergiant
|
|
https://www.w3.org/2000/01/rdf-schema#label
|
V1357 Cyg
|
|
gptkbp:locatedIn
|
gptkb:Milky_Way
|
|
gptkbp:massOfBlackHole
|
~21 solar masses
|
|
gptkbp:massOfCompanionStar
|
~19 solar masses
|
|
gptkbp:notableFor
|
first widely accepted black hole candidate
|
|
gptkbp:orbitType
|
5.6 days
|
|
gptkbp:otherName
|
gptkb:Cygnus_X-1
|
|
gptkbp:parallax
|
0.5111 mas
|
|
gptkbp:properMotionRA
|
-3.78 mas/yr
-6.40 mas/yr
|
|
gptkbp:radialVelocity
|
-5.4 km/s
|
|
gptkbp:rightAscension
|
19h 58m 21.675s
|
|
gptkbp:spectralType
|
gptkb:O9.7_Iab
|
|
gptkbp:variableType
|
binary star system
|
|
gptkbp:XRaySource
|
yes
|
|
gptkbp:bfsParent
|
gptkb:V1357_Cygni
|
|
gptkbp:bfsLayer
|
6
|