| 其他摘要 | ε Ophiuchi is a peculiarly red giant star, because solar-like oscillation has been observed in ε Ophiuchi. Its frequency is about 25-80μHz, and large separations is about 4.8μHz. The oscillation mode is p-mode. Because of the position of ε Ophiuchi in the Hertzsprung-Russell diagram,ε Ophiuchi is regarded as one of the red giant stars. The effective temperature and luminosity of it are 4887±100K and L=59±5L. It is important to observe the stellar oscillations and to study the stellar theory, because it can be used to prob the interior structure and limit the important parameters of star. The method is that when stellar oscillation frequencies, mode and the position in the HR diagram are determined, one can utilize the stellar structure and evolution theory and select some important parameters, such as mass, initial chemical abundance, convective parameter to construct the stellar models which can pass through the error box and then calculate the oscillation frequencies. If the frequencies and the mode of theory model can suit the observed, we can use the theory model to explore the stellar interior structure and the important parameters, such as mass, chemical abundance, age and convective parameter and so on. Astrophysical observation has observed a set of frequencies and the position of ε Ophiuchi, so we can make use of the stellar structure and evolution theory to prob the interior structure and limit the important parameters of star. Our aim is according to the observed oscillation frequencies of ε Ophiuchi and the position in the HR diagram to research the interior structure and the important parameters of ε Ophiuchi. The stellar structure and evolution are determined by the initial mass and the component of the chemical abundance and are affected by some condition such as how to do with the conviction, the stellar wind, rotation, magnetic field and so on. Because the mass ofε Ophiuchi is small and the velocity is low , the effect of two factors can be neglected in the theory models. Furthermore, the effect of magnetic field on the stellar structure and evolution is one of the unresolved problem. In our paper we only consider that how to select the suit initial mass and chemical abundance,especially metallicity and the mixing length to let the model from the zero age main sequence to reach the observed position of ε Ophiuchi in the HR diagram and use the data of the model to calculate the oscillation information. Finally, we check the theory frequencies whether or not suit the observed frequencies. If the theory frequencies can suit the observed well, we can get the information of the interior structure and the important parameters of ε Ophiuchi, such as mass, chemical abundance, age and convective parameter and so on. But in most cease, there is difference between the theory frequencies and the observed frequencies. It is necessary to analyze the reason. In our paper, we think that the difference between the theory frequencies and the observed frequencies is caused by the effect of g-mode on p-mode and the limitation of our own stellar models. |
修改评论