Figure 22-28:
Stars Orbiting Sagittarius A* The colored dots superimposed on this infrared image show the motion of seven stars in the vicinity of the unseen massive object (denoted by the yellow five-pointed star) at the position of the radio source Sagittarius A*. The orbits were measured over a 15-year period. Analysis of the orbits indicates that the stars are held in orbit by a black hole of 4.1 million solar masses. The blue dots for S0-16 show this star reached 4% the speed of light at its closest approach to the black hole.
Stars Orbiting Sagittarius A* The colored dots superimposed on this infrared image show the motion of seven stars in the vicinity of the unseen massive object (denoted by the yellow five-pointed star) at the position of the radio source Sagittarius A*. The orbits were measured over a 15-year period. Analysis of the orbits indicates that the stars are held in orbit by a black hole of 4.1 million solar masses. The blue dots for S0-16 show this star reached 4% the speed of light at its closest approach to the black hole.
(Keck/UCLA Galactic Center Group)