We discuss a revision of accretion activity and kinematics of the enigmatic isolated UX Ori type star RZ Psc. Previously, RZ Psc was known to possess only spectroscopic signatures of outflow in the low-excitation lines of alkali metals. The archival high-resolution spectra reveal a short-lived episode of magnetospheric accretion in the system observed via inverse P Cyg profiles at the Hα and Ca ii 8542 Å lines. The simultaneous presence of accretion and outflow signatures at Ca ii 8542 Å is suggestive of an accretion-driven origin of the RZ Psc wind. We argue that RZ Psc experiences matter ejection via the magnetic propeller mechanism but variable accretion episodes allow it to sometimes move in the magnetospheric accretion regime. The presence of the weak accretion in the system is also supported by the radiation of the hot accretion spot on the stellar surface observed spectroscopically at the deep photometric minimum of the star. The Galactic motion of RZ Psc calculated with new GAIA DR2 astrometric data suggests possible membership in Cas-Tau OB association with an age of t = 20 +3 −5 Myr.
We analyse spectroscopic and photometric observations of the eclipsing polar BS Tri. The polar’s light curve shape variations can be interpreted by changing contributions of the accretion stream to the integral radiation of the system. Based on the radial velocity curves of the irradiated part of the secondary, we refine the masses of the system components, M1 = 0.60 ± 0.04M⊙, M2 ≈ 0.12M⊙, and the orbital inclination, i = 85 ± 0.5○. The polar’s spectra reveal cyclotron harmonics forming in an accretion spot with a magnetic field strength of B = 22.7 ± 0.4 MG and an average temperature of T ∼ 10 keV. In addition to the cyclotron harmonics, the BS Tri spectra contain Zeeman components of Hα line, which are probably formed in the cool halo near the accretion spot. The orientation of the magnetic dipole and the coordinates of the accretion spot are estimated by modeling the light curves of the polar. We show that for a satisfactory description of the BS Tri light curves we have to take into account the variability of the spot’s optical depth along the line of sight. Doppler maps of BS Tri show a part of the accretion stream with a trajectory close to ballistic near the Lagrange point L1, and another part of the stream moving along the magnetic field lines. The estimate of the stagnation region position found from the Doppler tomograms is consistent with the photometric estimates of the accretion spot position.
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