The Proper Motion of Sagittarius A*. II. The Mass of Sagittarius A*

  title={The Proper Motion of Sagittarius A*. II. The Mass of Sagittarius A*},
  author={Mark J. Reid and Andreas Brunthaler},
  journal={The Astrophysical Journal},
  pages={872 - 884}
We report measurements with the Very Long Baseline Array (VLBA) of the position of Sgr A* with respect to two extragalactic radio sources over a period of 8 yr. The apparent proper motion of Sgr A* relative to J1745-283 is 6.379 ± 0.024 mas yr-1 along a position angle of 209.°60 ± 0.°18, almost entirely in the plane of the Galaxy. The effects of the orbit of the Sun around the Galactic center can account for this motion, and the residual proper motion of Sgr A* perpendicular to the plane of the… 

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