Stellar and Molecular Radii of a Mira Star: First Observations with the Keck Interferometer Grism
Stellar and Molecular Radii of a Mira Star: First Observations with the Keck Interferometer Grism
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米拉星的恒星和分子半径：用凯克干涉仪 Grism 进行的首次观测
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
A. Booth
中科院分区：
文献类型：
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作者：
Joshua A Eisner;James R. Graham;R. Akeson;E. Ligon;M. Colavita;G. Basri;K. Summers;S. Ragland;A. Booth
利用Keck干涉仪上的新棱镜，我们获得了Mira恒星R Vir的光谱分散（R ~ 230）干涉测量结果。这些数据表明，测量到的发射半径在2.0 ~ 2.4 μm之间变化很大。简单的模型可以利用扩展的分子层再现这些波长相关的变化，这些分子层吸收恒星辐射并以更长的波长重新发射。因为我们观察到光谱区域有或没有大量的分子不透明，我们确定了恒星光球半径，不受分子辐射的污染。我们推断，大多数分子的不透明性产生于大约两倍于恒星光球半径的地方。
Using a new grism at the Keck Interferometer, we obtained spectrally dispersed (R ~ 230) interferometric measurements of the Mira star R Vir. These data show that the measured radius of the emission varies substantially from 2.0 to 2.4 μm. Simple models can reproduce these wavelength-dependent variations using extended molecular layers, which absorb stellar radiation and reemit it at longer wavelengths. Because we observe spectral regions with and without substantial molecular opacity, we determine the stellar photospheric radius, uncontaminated by molecular emission. We infer that most of the molecular opacity arises at approximately twice the radius of the stellar photosphere.