We present an attempt to resolve for the first time one of the brightest long period variables in the globular cluster 47 Tuc with PIONIER in the H band. Based on model atmospheres and observations of local LPVs, the predicted visibilities were about 0.9,i.e. they are at the limit of feasibility with PIONIER. The observations show that the star is unresolved with an upper limit of 0.44 mas for the uniform disk (UD) diameter in the H band. This is in agreement with the predictions from stellar evolution models and from a dynamic model with similar stellar parameters. Spatial frequencies of B[m] / λ[μm] >150 are necessary to resolve this star and to distinguish between different models, but these are beyond those currently accessible with VLTI.
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机译：我们展示了尝试在H频段中的Pionier中首次解决最亮的长周期变量之一的最亮期变量。基于模型气氛和局部LPV的观察，预测的可见力约为0.9，即。它们处于与Pionier的可行性限制。观察结果表明，该恒星未得到顶部的上限为H频段中的均匀盘（UD）直径为0.44mas。这与恒星演化模型的预测和具有相似恒星参数的动态模型一致。 B [M] /λ[μm]> 150的空间频率是解决该星的必要条件，并区分不同的模型，但这些超出了目前与VLTI可访问的模型。
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