On the rotation of the Sun

Abstract

An asymptotic method is developed to estimate the rotational splitting of sectoral five-minute solar oscillations. Integral formulae are obtained which can be inverted to yield the variation with depth of the Sun’s angular velocity near the equatorial plane. The result is a functional of smoothed data, and does not rely on a detailed theoretical model of the Sun. The method has been tested with artificial data (computed from a theoretical solar model) of a kind similar to some real solar data obtained recently by Duvall & Harvey ( Nature, Lond . 310, 19 (1984)). The results are encouraging, for they reproduce at least the broadest feature of the somewhat arbitrary angular velocity with which the theoretical model was endowed. When applied to the real data, the method yields a result similar to that derived by Duvall et al. ( Nature, Lond . 310, 22 (1984)) by another procedure.