Astronomy & Space Science · AST-515
Milky Way Rotation & Dark Matter: Advanced Connections
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Overview
Advanced view of Milky Way Rotation & Dark Matter
The rotation of the Milky Way shows that visible stars and gas do not account for all of its gravitational mass. Orbital speeds remain high far from the Galactic center instead of declining as expected if most mass were concentrated in the luminous inner regions.
Milky Way dynamics constrain dark-matter halo shape and density, determine the Galaxy's total mass, and set the gravitational environment for stellar streams, satellites, and Solar-System motion through the Galaxy.
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- 01The Milky Way Galaxy — SummaryOpen source ↗
OpenStax Astronomy 2e
View claim-by-claim traceability3 verified claims
The rotation of the Milky Way shows that visible stars and gas do not account for all of its gravitational mass.
supported · checked Sep 22, 2026Measurements of neutral hydrogen, molecular masers, stellar velocities, satellite motions, and local stellar dynamics all require more gravitating mass than can be supplied by observed baryonic matter alone.
supported · checked Sep 22, 2026For a nearly spherical mass distribution, orbital speed depends on the mass enclosed within the orbit.
supported · checked Sep 22, 2026