We present the first visual orbit for the nitrogen-rich Wolf–Rayet binary, WR 133 (WN5o+O9I), based on observations made with the CHARA Array and the MIRC-X combiner. This orbit represents the first visual orbit for a WN star and only the third Wolf–Rayet star with a visual orbit. The orbit has a period of 112.8 days, a moderate eccentricity of 0.36, and a separation of a=0.79 mas on the sky. We combine the visual orbit with an SB2 orbit and Gaia parallax to find that the derived masses of the component stars are and , with the large errors owing to the nearly face-on geometry of the system combined with errors in the spectroscopic parameters. We also derive an orbital parallax that is identical to the Gaia-determined distance. We present a preliminary spectral analysis and atmosphere models of the component stars, and find the mass-loss rate in agreement with polarization variability and our orbit. However, the derived masses are low compared to the spectral types and spectral model. Given the close binary nature, we suspect that WR 133 should have formed through binary interactions, and represents an ideal target for testing evolutionary models given its membership in the cluster NGC 6871.

我们基于CHARA阵列和MIRC-X合成器的观测结果，提出了富氮Wolf-Rayet二元体WR 133（WN5o + O9I）的第一个视觉轨道。该轨道代表WN恒星的第一个视觉轨道，而仅代表具有视觉轨道的第三个Wolf-Rayet恒星。轨道的周期是112.8天，0.36适度的偏心，和一个分离一个= 0.79 MAS在天空。我们将视觉轨道与SB2轨道和盖亚视差相结合，发现派生的恒星质量为和，由于系统的近乎正面的几何形状以及光谱参数的误差而导致较大的误差。我们还推导了与Gaia确定的距离相同的轨道视差。我们提出了组成恒星的初步光谱分析和大气模型，并发现了与极化变率和我们的轨道一致的质量损失率。但是，与光谱类型和光谱模型相比，导出的质量较低。考虑到紧密的二进制性质，我们怀疑WR 133应该是通过二进制相互作用而形成的，并且鉴于其在簇NGC 6871中的成员资格，它代表了测试进化模型的理想目标。