We present new photometric and spectroscopic data on the low-mass, eclipsing binary star NSVS 11868841. Light and velocity data are analyzed and modeled. Resulting best-fit models indicate a change in the orbital period. Our 2019 October observation of secondary eclipse occurs 0.01042 days prior to that predicted by the latest published ephemeris when assuming a circular orbit. Our spectroscopic data from 2009 and 2019 yield a consistent systemic velocity of −9.78 ± 1.3 km s −1 and a mass ratio of 0.928 ± 0.016, both of which are significantly different than previous studies. Orbital period changes have not been indicated in earlier works either.

中文翻译：

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消除二元NSVS 11868841的光度和光谱分析

我们在低质量，黯淡的双星NSVS 11868841上提供了新的光度和光谱数据。对光和速度数据进行了分析和建模。得到的最佳拟合模型表明轨道周期发生了变化。我们在2019年10月观测到的次食发生在假设最新的星历表预测为圆形轨道之前0.01042天。我们从2009年和2019年获得的光谱数据得出一致的系统速度为-9.78±1.3 km s -1和质量比为0.928±0.016，两者均与以前的研究有显着差异。在早期的工作中也没有指出轨道周期的变化。