ABSTRACT
In preceding chapters, the ‘first order’ theory of surficial distortion in close binary systems was outlined. ‘First order’ here means that the effects of proximity in one component induced by the other are regarded as being due to a mass point, i.e. the surficial distortion of a component does not affect that of its companion. The description is self-consistent up to terms of order https://www.w3.org/1998/Math/MathML"> ( R / a ) 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315160429/bd124c76-0d70-4bbd-89e0-11be4a83f1d7/content/math4_1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where R is a stellar radius and a is the mean separation of the two stars. For a typical close binary system this ratio may be https://www.w3.org/1998/Math/MathML"> ~ 0.2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315160429/bd124c76-0d70-4bbd-89e0-11be4a83f1d7/content/math4_2.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , so that the error of the description may regarded as quite less than https://www.w3.org/1998/Math/MathML"> ~ 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315160429/bd124c76-0d70-4bbd-89e0-11be4a83f1d7/content/math4_3.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the effect. Until recently this would have been well below the measurement accuracy of proximity effects in the majority of such close pairs.
