(Abridged) Classical Be stars occasionally transition from having a gaseous circumstellar disk (''Be phase'') to a state in which all observational evidence for the presence of these disks disappears (''normal B-star phase''). We present one of the most comprehensive spectropolarimetric views to date of such a transition for two Be stars, pi Aquarii and 60 Cygni. 60 Cyg's disk loss episode was characterized by a monotonic decrease in emission strength over a time-scale of 1000 days, consistent with the viscous time-scale of the disk, assuming alpha is 0.14. pi Aqr's disk loss was episodic in nature and occurred over a time-scale of 2440 days. An observed time lag between the behavior of the polarization and H-alpha in both stars indicates the disk clearing proceeded in an ''inside-out'' manner. We determine the position angle of the intrinsic polarization to be 166.7 +/- 0.1 degrees for pi Aqr and 107.7 +/- 0.4 degrees for 60 Cyg, and model the observed polarization during the quiescent diskless phase of each star to determine the interstellar polarization along the line of sight. Minor outbursts observed during the quiescent phase of each star shared similar lifetimes as those previously reported for mu Cen, suggesting that the outbursts represent the injection and subsequent viscous dissipation of individual blobs of material into the inner circumstellar environments of these stars. We also observe deviations from the mean intrinsic polarization position angle during polarization outbursts in each star, indicating deviations from axisymmetry. We propose that these deviations might be indicative of the injection (and subsequent circularization) of new blobs into the inner disk, either in the plane of the bulk of the disk material or in a slightly inclined (non-coplanar) orbit.
Investigating the magnetospheric accretion process in the young pre-transitional disk system DoAr 44 (V2062~Oph). A multiwavelength interferometric, spectropolarimetric, and photometric observing campaign
Mapping the longitudinal magnetic field in the atmosphere of an active region plage from the inversion of the near-ultraviolet CLASP2.1 spectropolarimetric data
本研究利用 HanleRT 反演 CLASP2.1 近紫外 Mg II h & k 光谱偏振数据，绘制活动区谱斑与超半影的大气参数及纵向磁场，揭示二者加热机制的异同。
Spatial variations of the SrI 4607Åscattering polarization signals at subgranular scale observed with ZIMPOL at GREGOR telescope
Sr I 4607 γ谱线显示了可见太阳光谱中最强的散射偏振信号之一。这些信号的幅度预计会在粒度空间尺度上变化。这种变化可能是由于磁场强度和取向的变化（汉勒效应）以及由于等离子体性质的空间和时间变化。测量这种极化信号的空间变化将使我们能够研究亚晶区磁场的性质。但是，观测是具有挑战性的，因为同时需要高空间分辨率和高光谱偏振灵敏度。为了在颗粒尺度上测量这些空间变化的目的，我们用苏黎世成像偏振仪（ZIMPOL）在格里戈尔太阳望远镜上进行了分光偏振测量，在太阳盘面上的不同边缘距离。我们的研究结果表明，在颗粒尺度上，在每$μ$，从0.2到0.8，在Sr I 4607线的散射线偏振信号的空间变化。偏振信号幅度和连续强度之间的相关性在统计上意味着散射偏振在颗粒区域比在晶间通道中更高。
The circumstellar environment of the young, low-mass dipper star JH 223. Accretion and large-scale magnetic field topology
Universidade Federal de Minas Gerais（米纳斯吉拉斯联邦大学）；Université Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；California Institute of Technology（加州理工学院）；European Southern Observatory（欧洲南方天文台）；INAF - Osservatorio Astrofisico di Catania（意大利国家天体物理研究所卡塔尼亚天文台）；Crimean Astrophysical Observatory（克里米亚天体物理观测站）；Seoul National University（首尔国立大学）；SETI Institute（搜寻地外文明研究所）；Univ. de Toulouse（图卢兹大学）
Vector Magnetic Field associated with an Active Region Filament Observed by SUNRISE III/SCIP in the Ca II 8542 Å Line
Nagoya University（名古屋大学）；Institute for Space-Earth Environmental Research, Nagoya University（名古屋大学地球·宇宙环境研究所）；National Astronomical Observatory of Japan（日本国立天文台）；The Graduate University for Advanced Studies（高级研究院）；Kanazawa University（金泽大学）；Max Planck Institute for Solar System Research（马普太阳系研究所）；National Institute for Fusion Science（国立研究开发法人核融合科学研究所）
利用SUNRISE III/SCIP在Ca II 8542 Å谱线的高空间分辨率偏振观测，首次明确探测到暗条区域的线性极化信号，通过弱场近似得到约-80 G的视线磁场和300-500 G的横向磁场，为研究低层色球暗条矢量磁场结构提供了新窗口。
