An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 1 Search : Freeman''s law
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.

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