AE Ursae Majoris - a delta Scuti star in the Hertzsprung Gap
AE Ursae Majoris - a delta Scuti star in the Hertzsprung Gap
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AE Ursae Majoris - 赫兹普龙间隙中的一颗盾牌座δ星
DOI：
10.1093/mnras/stx125
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发表时间：
2017
影响因子：
4.8
通讯作者：
Zuo Fang
中科院分区：
文献类型：
--
作者：
Niu Jia Shu;Fu Jian Ning;Li Yan;Yang Xiao Hu;Zong Weikai;Xue Hui Fang;Zhang Yan Ping;Liu Nian;Du Bing;Zuo Fang
本文分析了在盾牌座δ星星大熊座AE（AE Uma）上收集到的光度数据和光谱数据。通过分析2009年至2012年40个夜晚的光变曲线，从频率内容中分别确定了基频和第一泛音频率f0 = 11.625 60 c d− 1和f1 = 15.031 24 c d−1。此外，另外37个频率被识别为谐波或基波和第一泛音频率的线性组合，其中25个是新检测到的。根据新测定的84个最大光时的O-C图，结合文献资料，确定了基模的周期变化率为（1/P0）（dP 0/dt）= 5.4（±1.9）× 10− 9 yr − 1。光谱数据表明，UMa是一颗第一星族δ Scuti星星。利用这些物理性质，我们基于恒星演化密码对该目标进行了理论探索，认为脉动周期的变化是由长期演化效应引起的。最后，我们用以下物理参数来约束UMa：质量1.805 ± 0.055 M Ω，半径1.647 ± 0.032 × 10 ~（11）cm，光度1.381 ± 0.048（logL/L Ω），年龄1.055 ± 0.095 × 10 ~（19）yr。AE Uma可能是（星族I）Scuti δ星星，它位于其演化轨道第二次离开主序星之后，是一颗处于赫茨弹簧间隙阶段的星星，具有氦核和燃烧氢的外壳。
We analyse the photometric data and spectroscopic data collected on the δ Scuti star AE Ursae Majoris (AE UMa). The fundamental and the first overtone frequencies are confirmed asf0= 11.625 60 c d−1andf1= 15.031 24 c d−1, respectively, from the frequency content by analysing light curves over 40 nights, spanning from 2009 to 2012. Additionally, another 37 frequencies are identified as either the harmonics or the linear combinations of the fundamental and the first overtone frequencies, among which 25 are newly detected. The rate of period change of the fundamental mode is determined as (1/P0)(dP0/dt) = 5.4(±1.9) × 10−9yr−1as revealed from the O − C diagram based on the 84 newly determined times of maximum light combined with those derived from the literature. The spectroscopic data suggest that AE UMa is a Population I δ Scuti star. With these physical properties, we perform theoretical explorations based on the stellar evolution codemesaon this target, considering that the variation of pulsation period is caused by secular evolutionary effects. We finally constrain AE UMa with physical parameters as follows: mass of 1.805 ± 0.055 M⊙, radius of 1.647 ± 0.032 × 1011cm, luminosity of 1.381 ± 0.048(logL/L⊙) and age of 1.055 ± 0.095 × 109yr. AE UMa can be the (Population I) δ Scuti star that locates just after the second turn-off of its evolutional track leaving the main sequence, a star in the phase of the Hertzsprung Gap with a helium core and a hydrogen-burning shell.