Changes

  |bibcode=2009ApJ...692.1075G

  |bibcode=2009ApJ...692.1075G

  |ref=harv

  |ref=harv

}}</ref> Since 1995, astronomers have tracked the motions of 90 stars orbiting an invisible object coincident with the radio source in the center of our galaxy, Milky way. The astronomers were able to infer that a 2.6 million {{Solar mass|link=y}} object must be contained in a volume with a radius of 0.02 [[light-year]]s to cause the motions of those stars.<ref name="Ghez1998">{{cite journal

}}</ref> Since 1995, astronomers have tracked the motions of 90 stars orbiting an invisible object coincident with the radio source in the center of our galaxy, Milky way. The astronomers were able to infer that a 2.6 million sollar mass object must be contained within the radius of 0.02 [[light-year]]s to cause the motions of those stars.<ref name="Ghez1998">{{cite journal

  |last1=Ghez |first1=A. M.

  |last1=Ghez |first1=A. M.

  |last2=Klein |first2=B. L.

  |last2=Klein |first2=B. L.