EDP Sciences
Free access
Issue
A&A
Volume 492, Number 3, December IV 2008
Page(s) L49 - L52
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200809364


A&A 492, L49-L52 (2008)
DOI: 10.1051/0004-6361:200809364

Letter

A new asteroseismic diagram of solar-like stars

Y. K. Tang1, 2, S. L. Bi3, and N. Gai3

1  Department of Physics, Dezhou University, Dezhou 253023, PR China
    e-mail: tyk450@163.com; bisl@bnu.edu.cn
2  Key Lab of Biophysics in Universities of Shandong, Dezhou 253023, PR China
3  Department of Astronomy, Beijing Normal University, Beijing 100875, PR China

Received 8 January 2008 / Accepted 13 November 2008

Abstract
Aims. We attempt to develop a new asteroseismic diagram and investigate its characteristics, based on the ratio “r01” of adjacent, average, small separations.
Methods. The ratio r01 is defined following the asymptotic formula of stellar p-modes. Using the low-degree, theoretical, numerical value of adiabatic frequencies of stellar model, we compute the ratio r01 and construct an additional asteroseismic diagram.
Results. The additional asteroseismic diagram, which is similar to the C-D diagram (i.e. the famous asteroseismic HR diagram, so-called Christensen-Dalsgaard diagram), represents a composite of the average, large separations $\langle\Delta\nu\rangle$ and the ratio r01 of the adjacent, small separations. A distinct separation is identified between the effects of varying both mass and age. The diagram can therefore provide information that is complementary to that provided by a C-D diagram, which can be used to estimate directly both the stellar mass and evolutionary state. Interestingly, the age of star can be derived from the new asteroseismic diagram. Furthermore, we investigate the parameter r01, which can be a useful direct indicator of stellar age.


Key words: stars: evolution -- stars: oscillations



© ESO 2008