The size of AB Doradus A from VLTI/AMBER interferometry
The size of AB Doradus A from VLTI/AMBER interferometry
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来自 VLTI/AMBER 干涉测量的 AB Doradus A 的尺寸
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
J. Montalbán
中科院分区：
文献类型：
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作者：
J. Guirado;J. Marcaide;I. Martí;J. L. Bouquin;L. Close;W. Cotton;J. Montalbán
前主序(PMS)星AB Dor A是四重系统AB Doradus的主要组成部分。AB Dor A、AB Dor C的近伴星质量和光度的精确测定，为低质量恒星理论演化模型的定标提供了重要的基准。限制这种校准精度的因素是系统的年龄，因为AB Dor A和C的质量和光度都被其他正在进行的计划很好地监测到了。在这篇文章中，我们给出了AB Dor A的VLTI/琥珀观测，它提供了这颗恒星的大小的直接测量，0.96±0.06R�。后一种估计，结合其他也为这颗恒星测量的基本参数，允许使用H-R图和质量-半径关系对PMS演化模型进行精确测试。我们发现我们的半径测量值大于模型的预测值，我们将其解释为AB Dor A的强磁活动产生超大尺寸的证据，至少部分考虑到这种磁性效应，理论等时线被用来推导AB Dor A的年龄限制，该系统的年龄约为40-50 Myr。我们的数据并没有完全排除年龄较大的人。
The pre-main sequence (PMS) star AB Dor A is the main component of the quadruple system AB Doradus. The precise determination of the mass and photometry of the close companion to AB Dor A, AB Dor C, has provided an important benchmark for calibration of theoretical evolutionary models of low-mass stars. The limiting factor to the precision of this calibration is the age of the system, as both the mass and luminosity of AB Dor A and C are well monitored by other ongoing programs. In this paper we present VLTI/AMBER observations of AB Dor A which provide a direct measurement of the size of this star, 0.96 ± 0.06R� . The latter estimate, combined with other fundamental parameters also measured for this star, allows a precise test of PMS evolutionary models using both H-R diagrams and mass-radius relationships. We have found that our radius measurement is larger than that predicted by the models, which we interpret as an evidence of the oversizing produced by the strong magnetic activity of AB Dor A. Considering, at least partially, this magnetic effect, theoretical isochrones have been used to derive constraints to the age of AB Dor A, favouring an age about 40–50 Myr for this system. Older ages are not completely excluded by our data.