The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer
The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer
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边缘变暗的大角星：使用 IOTA/IONIC 干涉仪成像
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
W. Traub
中科院分区：
文献类型：
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作者：
Sylvestre Lacour;Sylvestre Lacour;S. Meimon;É. Thiébaut;Guy Perrin;T. Verhoelst;T. Verhoelst;Ettore Pedretti;P. Schuller;P. Schuller;L. Mugnier;J. D. Monnier;J. Berger;X. Haubois;A. Poncelet;G. L. Besnerais;K. Eriksson;R. Millan;Sam Ragland;M. Lacasse;W. Traub;W. Traub
目标。我们对大角星进行了 H 波段干涉检查，这颗恒星经常用作空间和光谱校准器。
方法。使用 IOTA 3 望远镜干涉仪，我们对大角星进行了光谱干涉观测（R ≈ 35）。
将大气模型和规定与数据进行拟合，得出光球层的亮度分布。图像重建
使用两种软件算法进行：Wisard 和 Mira。
结果。消色差幂律被证明是亮度分布的良好模型，其边缘变暗与
一种是使用我们的 marcs 模型从大气模型模拟中得出的。得出的 Rosseland 直径为 21.05 ± 0.21，
对应于 Teff = 4295 ± 26 K 的有效温度。在闭合阶段没有检测到伴星，其上部
1 AU 时亮度比限制为 8 × 10^−4。距光球层一定距离处的动态范围确定为
1.5 × 10^−4 (1σrms)。还得出了光球层中存在的亮度不对称程度的上限 1.7×10^−3。
Aims. We undertook an H band interferometric examination of Arcturus, a star frequently used as a spatial and spectral calibrator.
Methods. Using the IOTA 3 telescope interferometer, we performed spectro-interferometric observations (R ≈ 35) of Arcturus.
Atmospheric models and prescriptions were fitted to the data to derive the brightness distribution of the photosphere. Image reconstruction
was performed using two software algorithms: Wisard and Mira.
Results. An achromatic power law proved to be a good model of the brightness distribution, with a limb darkening compatible with
the one derived from atmospheric model simulations using our marcs model. A Rosseland diameter of 21.05 ± 0.21 was derived,
corresponding to an effective temperature of Teff = 4295 ± 26 K. No companion was detected from the closure phases, with an upper
limit on the brightness ratio of 8 × 10^−4 at 1 AU. The dynamic range at such distance from the photosphere was established as
1.5 × 10^−4 (1σrms). An upper limit of 1.7×10^−3 was also derived for the level of brightness asymmetries present in the photosphere.