A new estimate of the solar core rotation from IPHIR.

Abstract

The effect of a rigidly rotating core on frequency splitting is shown to be approximately the same for all the observed low-degree modes. It is suggested that, in analysing poorly resolved rotationally split multiplets in oscillation power spectra, one should first determine a single value for the splitting instead of estimating the splitting for individual modes separately. By using this technique for fitting lines with l = 1, 2 of the IPHIR spectra, a mean sidereal splitting of 0.468 ± 0.036 and of 0.427 ± 0.046 μHz has been obtained for the green and red channels of the IPHIR photometer, respectively