AST-511beginner

Milky Way Rotation & Dark Matter: Foundations

The rotation of the Milky Way shows that visible stars and gas do not account for all of its gravitational mass. 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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Milky Way Rotation & Dark Matter: Foundations

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AST-510The Galactic Center & Sagittarius A*: Advanced Connections→

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AST-512Milky Way Rotation & Dark Matter: Structures & Vocabulary→

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The rotation of the Milky Way shows that visible stars and gas do not account for all of its gravitational mass.

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For a nearly spherical mass distribution, orbital speed depends on the mass enclosed within the orbit.

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Measurements 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.