Observations of stellar proper motions near the Galactic Centre

  title={Observations of stellar proper motions near the Galactic Centre},
  author={Andreas Eckart and Reinhard Genzel},
EVIDENCE for a massive black hole at the centre of our Galaxy has been accumulating for the past two decades 1−7. Estimates of the mass of this region have hitherto been based on the spectroscopic determination of radial velocities for stars and gas near the Galactic Centre, combined with the assumption that the stars are moving on largely circular, isotropically distributed orbits. But if this assumption is incorrect, the observations can be explained with a much smaller central mass, perhaps… 

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