Scientists of the Harvard-Smithsonian center for astrophysics have determined the rotation rate of the milky Way around its axis at the point where the Sun is.
In their work the authors chose between the two ways of determining the speed of rotation of the milky Way around its axis. The first method leads to a value of 220 kilometers per second, the second to 240 kilometers per second.
Scientists are inclined to believe that the second method gives a more correct estimate of the speed of rotation of the galactic disk with a radius equal to the distance from the center of the milky Way to the Sun.
The rotation curve describing the dependence of the orbital velocity of stars and gas as a function of the distance to the center of the milky Way best explained by the second observation.
The first method is based on measuring the maximum speed of emission of neutral hydrogen as a function of galactic longitude. Second — radiointerferometry with superlong bases and related BeSSeL (Bar and Spiral Structure Legacy) and VERA (VLBI Exploration of Radio Astrometry).