The frequency separations of stellar p-modes

¹ Department of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454003, PR China e-mail: yangwuming@ynao.ac.cn
² National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, PR China
³ Graduate School of the Chinese Academy of Sciences, Beijing 100039, PR China
⁴ Department of Astronomy, Beijing Normal University, Beijing 100875, PR China e-mail: bisl@bnu.edu.cn

Received: 11 January 2007
Accepted: 12 June 2007

Abstract

Aims.The purpose of this work is to investigate the characteristics of a new frequency separation of stellar p-modes.

Methods.Frequency separations are deduced from the asymptotic formula of stellar p-modes. Then, using the theoretical adiabatic frequencies of stellar model, we compute the frequency separations.

Results.A new separation , which is similar to the scaled small separation , is obtained from the asymptotic formula of stellar p-modes. The separations and have the same order. And like the small separation, is mainly sensitive to the conditions in the stellar core. However, with the decrease in the central hydrogen abundance of stars, the separations and deviate more and more from the scaled small separation. This characteristic could be used to extract the information on the central hydrogen abundance of stars.