We present the results of a numerical study of the fluid f, p and the gravitational w modes for increasingly relativistic non-rotating polytropes. The results for f and w modes are in good agreement with previous data for uniform density stars, which supports an understanding of the nature of the gravitational wave modes based on the uniform density data. We show that the p modes can become extremely long-lived for some relativistic stars. This effect is attributed to the change in the perturbed density distribution as the star becomes more compact.

Author notes

Present address: Institut fur Astronomie und Astrophysik, Universitat Tubingen, Auf der Morgenstelle 10, D-72076 Tubingen, Germany.