Physical properties of γ Doradus pulsating stars and their relationship with long-period δ Scuti variables

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2019,（1）
• 页码范围: 1-20
• 页数: 20页
• 语种: 英文
• DOI: 10.1088/1674-4527/19/1/1

摘要

We present LAMOST data on 168 γ Doradus (γ Dor) pulsating stars including stellar atmospheric parameters of 137 variables and spectral types for all of the samples.The distributions of period (P),temperature (T),gravitational acceleration (log(g)) and metallicity [Fe/H] are shown.It is found that most γ Dor variables are main-sequence stars with early F spectral types and temperatures from 6880 K to 7280 K.They are slightly more metal poor than the Sun with a metallicity range from-0.4 to 0.On the H-R and logg-T diagrams,both the γ Dor and δ Scuti (δ Sct) stars occupy in the same region and some are beyond the borders predicted by current stellar pulsation theories.It is discovered that the physical properties of γ Dor stars are similar to those of long-period δ Sct (P ＞ 0.3 d) stars.The stellar atmospheric parameters are all correlated with the pulsation period for short-period δ Sct variables (P ＜ 0.3 d),but there are no such relations for γ Dor or long-period δ Sct stars.These results reveal that γ Dor and long-period δ Sct are the same group of pulsating stars and they are different from short-period δ Sct variables.Meanwhile,33 γ Dor stars are identified as candidates of binary or multiple systems.