Astronomy & Space Science · AST-331
Apparent & Absolute Magnitude: Foundations
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Overview
Core model: Apparent & Absolute Magnitude
Apparent magnitude describes how bright an astronomical source appears from Earth, while absolute magnitude standardizes intrinsic brightness by asking how bright the source would appear at a reference distance of 10 parsecs. The magnitude scale is logarithmic and runs backward: smaller or more negative values are brighter.
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References & evidence
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- 01The Stars: A Celestial Census — SummaryOpen source ↗
OpenStax Astronomy 2e
View claim-by-claim traceability3 verified claims
Observed flux falls approximately with the inverse square of distance for an unobscured source.
supported · checked Sep 22, 2026Parallax gives distances to nearby stars, allowing their apparent fluxes to be converted into intrinsic luminosities and absolute magnitudes.
supported · checked Sep 22, 2026Apparent magnitude describes how bright an astronomical source appears from Earth, while absolute magnitude standardizes intrinsic brightness by asking how bright the source would appear at a reference distance of 10 parsecs.
supported · checked Sep 22, 2026