2021MNRAS.507.5805A

We present a dynamical study of the intermediate polar and dwarf nova cataclysmic variable GK Persei (Nova Persei 1901) based on a multisite optical spectroscopy and R-band photometry campaign. The radial velocity curve of the evolved donor star has a semi-amplitude K₂=126.4 ±0.9 km s^–1 and an orbital period P = 1.996872 ±0.000009 d. We refine the projected rotational velocity of the donor star to v_rot sini = 52 ±2 km s^–1 that, together with K₂, provides a donor star to white dwarf mass ratio q = M₂/M₁ = 0.38 ± 0.03. We also determine the orbital inclination of the system by modelling the phase-folded ellipsoidal light curve and obtain i = 67° ± 5°. The resulting dynamical masses are M₁ = 1.03^+0.16_–0.11 M_☉ and M₂ = _0.39+0.07^_–0.06 M_☉ at 68 per cent confidence level. The white dwarf dynamical mass is compared with estimates obtained by modelling the decline light curve of the 1901 nova event and X-ray spectroscopy. The best matching mass estimates come from the nova light curve models and an X-ray data analysis that uses the ratio between the Alfven radius in quiescence and during dwarf nova outburst.