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Comment by thrance

3 days ago

We can infer the general distribution of mass on the other side of the galaxy from observing the trajectory of stars, can't we?

It takes 230 million years for the Sun to make one full orbit around the Milky Way.

  • huh? how can sun orbit the milky way if it is within the milky way

    • The same way that the Earth can orbit the centre of mass of the solar system and also be within the solar system. We say that the Earth orbits the Sun because that's where 99.86% of the mass of the solar system is located.

      The Sun in turn orbits the the centre of mass of the Milky Way. But I don't think that the mass of the Milky way's central supermassive black hole dominates in the same way.