X-ray properties of the white dwarf pulsar eRASSU J191213.9−441044

We report X-ray observations of the newly discovered pulsating white dwarf eRASSU J191213.9-441044 with Spectrum Roentgen Gamma and eROSITA (SRG/eROSITA) XMM-Newton. The new source was during first all-sky survey at a flux level fX (0.2 - 2.3 keV) = 3.3 e-13 erg cm-2 s-1 found to be spatially coincident G 17.1 stellar Gaia-source distance 237 pc. dropped about 1 three following surveys remained this lower dedicated XMM-Newton performed in September 2022. With XMM-Newton, pulsations period 319 s were ultraviolet wavelengths occurring simultaneously time, thus confirming nature as second white-dwarf pulsar. UV-pulses correspond broad optical pulses. Narrow pulses that occurred occasionally simultaneous XMM-Newton/ULTRACAM have no counterpart. orbital variability signal roughly sinusoidal shape observed pulsed fraction ~28% maximum emission phase ~0.25. light curve peaks around binary 0.45. spectrum can described sum power law thermal component mean luminosity Lx(0.2-10 1.4 e30 s-1. spectral properties could indicate some residual accretion, contrast case prototypical object AR Sco.