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Will a black hole revolve around a non-black hole object with greater mass?

  1. May 6, 2010 #1
    i'm just wondering if a black hole orbits around a greater mass or will the greater mass revolve around it?
  2. jcsd
  3. May 6, 2010 #2
    Contrary to what many believe, stars and black holes do not remain stationary as objects revolve around them. While the earth is revolving around the sun, the entire solar system is actually turning around its center of mass. Since the sun has much more mass than the planets, the sun's movement is barely noticeable.

    So a black hole is just an incredibly massive thing, and assuming the other, even more massive object doesn't collapse in on itself due to gravity, both would rotate around the center of mass of the system.
  4. May 6, 2010 #3


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    Indeed, Cynus X-1, the best and longest known black hole, is a binary system. The black hole of about 8.7 solar masses seems to be orbiting a star of about 20-40 solar masses.

    Note that, as livect points out: even the most massive object will orbit its smaller companions. Earth orbits around a point called the barycentre of the Earth-Moon system. The Sun orbits the Sun-Jupiter barycentre.

    Last edited by a moderator: Apr 25, 2017
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