To improve the statistics of hierarchical multiplicity, secondary components of wide nearby binaries with solar-type primaries were surveyed at the SOAR telescope for evaluating the frequency of subsystems. Images of 17 faint secondaries were obtained with the SOAR Adaptive Module that improved the seeing; one new 0.2" binary was detected. For all targets, photometry in the g', i', z' bands is given. Another 46 secondaries were observed by speckle interferometry, resolving 7 close subsystems. Adding literature data, the binarity of 95 secondary components is evaluated. We found that the detection-corrected frequency of secondary subsystems with periods in the well-surveyed range from 10^3 to 10^5 days is 0.21+-0.06, same as the normal frequency of such binaries among solar-type stars, 0.18. This indicates that wide binaries are unlikely to be produced by dynamical evolution of N-body systems, but are rather formed by fragmentation.
Non-thermal Sources from Stereoscopic Hard X-ray and Earth-based Microwave Observations in a Data-Constrained Magnetohydrodynamic Simulation
New Jersey Institute of Technology（新泽理工学院）；Institute for Space-Earth Environmental Research, Nagoya University（名古屋大学地球·宇宙环境研究所）；University of Applied Sciences and Arts Northwestern Switzerland（瑞士西北应用科学艺术大学）；ETH Zürich（苏黎世联邦理工学院）；Space Sciences Laboratory, University of California（加州大学空间科学实验室）
Southern massive stars at high angular resolution: WR 25 is a massive hierarchical triple system
KU Leuven（荷语鲁汶大学）；Leuven Gravity Institute, KU Leuven（荷语鲁汶大学引力研究所）；Royal Observatory of Belgium（比利时皇家天文台）；European Southern Observatory（欧洲南方天文台）；The CHARA Array of Georgia State University（佐治亚州立大学CHARA阵列）；Institut de Planétologie et d’Astrophysique de Grenoble（格勒诺布尔行星学与天体物理学研究所）；Tel Aviv University（特拉维夫大学）
IZ Tel and UW Vir: Southern oscillating eclipsing Algol systems with active mass transfer
Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens（雅典国家天文台天文学、天体物理学、空间应用与遥感研究所）；The University of Queensland（昆士兰大学）；Astronomical Association of Queensland（昆士兰天文协会）；Çanakkale Onsekiz Mart University（恰纳卡莱18马月大学）
The HARPS search for southern extra-solar planets. XLVII. Five Jupiter-mass planets in long-period orbits, one highly irradiated Neptune, one brown dwarf, and five stellar binaries
