Assertion: andromeda's star | /r/HasProperty | black hole
Facets:
Source sentences:
text: It is a binary system that contains a blue supergiant variable star and the x-ray source thought to be the black hole.
text: The Rev. John Michell of Thornhill published work in 1767 on the distribution of double stars, and in 1783 on "dark stars" (black holes), that may have influenced Herschel.