An Etymological Dictionary of Astronomy and Astrophysics

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فرهنگ ریشه‌شناختی اخترشناسی-اخترفیزیک

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Freeman's law
  قانون ِ فریمن  
qânun-e Freeman
Fr.: loi de Freeman  

A statistical finding about “normal” → spiral galaxies,
whereby there is an upper limit on the mean central → surface brightness of disks. This value is constant for different spiral types, amounting to
21.65 ± 0.30 mag arcsec2 in the B band.

See also: Named after K. C. Freeman (1970, Ap.J. 160, 811); → law.