We present the first detailed X-ray study and simultaneous optical observations of the active fast rotating star FR Cnc. The X-ray spectra are found to be explained by two-temperature plasma model with temperature of cool and hot components of 0.34 and 1.1 keV, respectively. The X-ray light curve in the 0.5–2.0 keV energy band is found to be rotationally modulated with the degree of rotational modulation of \(\sim\)17%. We have also found that the X-ray light curve is anti-correlated with the optical light and colour curves in the sense that maximum X-ray light corresponds to minimum optical light and cooler region on the surface of FR Cnc. The X-ray luminosity of FR Cnc is found to be almost consistent in the last 30 years with an average value of \(4.85\times 10^{29}\) erg \(\hbox {s}^{-1}\) in the 0.5–2.0 keV energy band.

我们首次对活跃的快速旋转恒星 FR Cnc 进行了详细的 X 射线研究和同步光学观测。发现 X 射线光谱可以用冷和热成分的温度分别为 0.34 和 1.1 keV 的双温度等离子体模型来解释。发现 0.5-2.0 keV 能带中的 X 射线光曲线被旋转调制，旋转调制程度为\(\sim\) 17%。我们还发现，在最大 X 射线光对应于 FR Cnc 表面上的最小光学光和较冷区域的意义上，X 射线光曲线与光学光和颜色曲线是反相关的。发现FR Cnc的X射线光度在过去30年中几乎一致，平均值为\(4.85\times 10^{29}\) erg\(\hbox {s}^{-1}\)在 0.5–2.0 keV 能带中。