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تسجيل

Astrophysical estimates

المؤلف:  James Binney and Michael Merrifield

المصدر:  GALACTIC ASTRONOMY

الجزء والصفحة:  P-86

2026-09-07

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For many astrophysically interesting stellar types, none of the direct methods ... can be applied, and yet even an approximate estimate of the radii of these stars can be of enormous importance for an understanding of stellar structure and evolution. In such cases, we can estimate radii by means of Stefan's law for black-body radiation if we know a star's luminosity (from its apparent magnitude and distance) and its effective temperature (from spectroscopic evidence) . Such estimates, although not fundamental measurements, can nevertheless be quite accurate and useful.