中国科学院云南天文台机构知识库

The DAV star 8808 was observed by 13 different telescopes for more than 170 h in 2009 April on the WET run XCOV26. 25 independent pulsation frequencies were identified by this data set. We assumed 19 m = 0 modes and performed an asteroseismological study on those 19 modes. We evolve grids of DAV star models by WDEC adopting the element diffusion scheme with pure and screened Coulomb potential effect. The core compositions are from white dwarf models evolved by MESA, which are thermal nuclear burning results. Our best-fitting model is from the screened Coulomb potential scenario, which has parameters of log(M-He/M-* = -2.4, log(M-H/M-*) = -5.2, T-eff = 11100 K, M-* = 0.710 M-circle dot, logg = 8.194, and sigma(Rms) = 2.86 s. The value of sigma(Rms) is the smallest among the four existing asteroseismological work. The average period spacing is 46.299 s for not equal 1 modes and 25.647 s for not equal 2 modes. The other six observed modes can be fitted by m not equal 0 components of some modes for our best-fitting model. Fitting the 25 observed modes, we obtain a a RN's value of 2.59 s. Considering the period spacings, we also assume, that at least in one case, we detect an 1= 2 trapped mode.