Astronomy & Space Science · AST-506
The Galactic Center & Sagittarius A*: Foundations
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Overview
Core model: The Galactic Center & Sagittarius A*
At the dynamical center of the Milky Way lies Sagittarius A*, a compact radio source associated with a supermassive black hole of roughly four million solar masses. The central few parsecs also contain dense star clusters, ionized gas, molecular material, magnetic structures, and extreme tidal and radiation environments.
Evidence behind this section3 claims
At the dynamical center of the Milky Way lies Sagittarius A*, a compact radio source associated with a supermassive black hole of roughly four million solar masses.
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References & evidence
Source library for this chapter
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- 01The Milky Way Galaxy — SummaryOpen source ↗
OpenStax Astronomy 2e
View claim-by-claim traceability3 verified claims
At the dynamical center of the Milky Way lies Sagittarius A*, a compact radio source associated with a supermassive black hole of roughly four million solar masses.
supported · checked Sep 22, 2026Stars orbit the central mass under strong gravity, while gas falling inward can heat and radiate before reaching the black hole.
supported · checked Sep 22, 2026Decades of infrared astrometry track individual stars completing fast elliptical orbits around an unseen compact mass.
supported · checked Sep 22, 2026