我们的目标是识别可变X射线源3XMM J000511.8+634018，这是在编制3XMM目录时通过常规检查偶然发现的。我们分析了源的档案XMM-牛顿观测，获得了三种颜色的BUSCA测光，并使用LBT进行了光谱学分析。这些数据得到了兹威基瞬态设施的档案观测的补充。根据其光学和X射线性质，3XMM J000511.8+634018被归类为一颗磁性激变变星或极地变星。流量调制的周期为2.22小时（8009.1 +- 0.2秒），我们确定与轨道周期。从一个周期到下一个周期，明亮的相位在X射线光度上变化很大。该源显示了典型的极地热等离子体光谱，没有发光的软黑体成分的证据。它是不食的，并显示单极吸积。X射线和BUSCA光变曲线显示出气流吸收下降，这表明倾角为50度< i <75度。这一特征的定相发生在亮相的末尾，需要一种有点特殊的吸积几何形状，在白矮星被磁引导之前，有一股流绕着它运行很远。这个极地的周期落在激变变星的周期间隙（2.15-3.18小时）内，但似乎落在仅考虑极地时的最小周期之下。
英文摘要：
We aimed to identify the variable X-ray source 3XMM J000511.8+634018, which was serendipitously discovered through routine inspections while the 3XMM catalogue was compiled. We analysed the archival XMM-Newton observation of the source, obtained BUSCA photometry in three colours, and performed optical spectroscopy with the LBT. These data were supplemented by archival observations from the Zwicky Transient Facility. Based on its optical and X-ray properties, 3XMM J000511.8+634018 is classified as a magnetic cataclysmic variable, or polar. The flux is modulated with a period of 2.22 hr (8009.1 +- 0.2 s), which we identify with the orbital period. The bright phases are highly variable in X-ray luminosity from one cycle to the next. The source shows a thermal plasma spectrum typical of polars without evidence of a luminous soft blackbody-like component. It is non-eclipsing and displays one-pole accretion. The X-ray and BUSCA light curves show a stream absorption dip, which suggests an inclination 50degr < i < 75degr. The phasing of this feature, which occurs at the end of the bright phase, requires a somewhat special accretion geometry with a stream running far around the white dwarf before it is magnetically channelled. The period of this polar falls within the period gap of the cataclysmic variables (2.15-3.18 h), but appears to fall just below the minimum period when only polars are considered.
Multi-band study of RX J0838-2827 and XMM J083850.4-282759: a new asynchronous magnetic cataclysmic variable and a candidate transitional millisecond pulsar
