标题： 年龄约为20Myr的UXOR型变星RZ Psc吸积活动的耀发活动 显示英文标题

标题： Flares of accretion activity of the 20 Myr old UXOR RZ Psc

摘要： 我们讨论了神秘的孤立UX大陵型星RZ Psc吸积活动和动力学的修正。此前，RZ Psc仅被知具有碱金属低激发线中喷流的光谱特征。存档的高分辨率光谱揭示了通过H$\alpha$和CaII 8542$\unicode{x212B}$线以反向P Cyg轮廓观测到的系统中短暂的磁层吸积事件。同时在CaII 8542$\unicode{x212B}$处存在吸积和喷流特征，暗示RZ Psc风的吸积驱动起源。我们认为，RZ Psc通过磁场推进机制经历物质抛射，但可变的吸积事件允许它有时进入磁层吸积状态。系统的微弱吸积的存在也由恒星表面的高温吸积斑点的辐射支持，该斑点在恒星的深光度最小值处被光谱观测到。用新的GAIA DR2天文学数据计算的RZ Psc的银河运动表明可能属于Cas-Tau OB协会，年龄为$t=20^{+3}_{-5}$百万年。 显示英文摘要

摘要： 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 H$\alpha$ and CaII 8542 $\unicode{x212B}$ lines. The simultaneous presence of accretion and outflow signatures at CaII 8542 $\unicode{x212B}$ 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.