(abridged) We want to provide further evidence of the origin of the proposed stellar members of Chamaeleon and to identify interlopers from the foreground εCha and ηCha associations. To this aim, we compile lists of spectroscopically confirmed members of Chamaeleon I and II, εCha and ηCha, and of background objects in the same line of sight. Using Virtual Observatory tools, we cross-match these lists with the UCAC3 catalogue to get the proper motions of the objects. In the vector point diagram, we identify the different moving groups, and use this information to study the membership of proposed candidate members of the associations from the literature. For those objects with available radial velocities, we compute their Galactic space velocities. We look for correlations between the known properties of the objects and their proper motions. The members of the dark clouds exhibit clearly different proper motions from those of the foreground associations and of the background stars. The data suggest that Chamaeleon II could have different dynamical properties from Chamaeleon I. Although the two foreground clusters εand ηChamaeleontis constitute two different proper motion groups, they have similar spatial motions, which are different from the spatial motion of Chamaeleon I. On the other hand, the space motions of the Chamaeleon II stars look more similar to those of the foreground clusters than to the Chamaeleon I stars, but the numbers are low. Hence, with the available data it is unclear to what extent the stellar populations in both clouds are physically connected to each other. We find no correlations between the proper motions and the properties of the objects in either of the clouds.
Spectroscopy of close visual binary components of the stable shell star 1 Del
稳定壳层星是研究Be星盘形成基本物理原理的理想对象。如果这些恒星有一个近距离的未分辨的伴星，它对圆盘模型的贡献就不能被忽视，就像有时所做的那样。这项研究的目的是光谱解析近距离可见双星Be（壳）星1 Del，到目前为止，它只能通过散斑或显微测量来解析。使用了欧洲南方天文台（ESO）VLT望远镜的SINFONI摄谱仪在红外区域获得的积分场光谱;我们用Ondrejov天文台的Perek望远镜的可见光谱补充了这些观测。成功地解决了1 Del的光谱，并首次获得了1 Del B的光谱。我们发现1 Del A是一颗Be/shell星，而1 Del B不是一颗发射线天体。
New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools: Part I: UKIDSS LAS DR5 vs SDSS DR7
该项目的目的是提高我们对低质量和低金属丰度群体的认识，以调查金属丰度对恒星（和亚恒星）质量函数的影响。我们提出了一个光度和自行搜索的结果，旨在发掘超冷次矮星在大规模的调查。我们采用并结合了UKIDSS LAS DR 5和SDSS DR 7，并补充了来自2 MASS、DENIS和SuperCOSMOS的辅助数据。SDSS DR 7与UKIDSS LAS DR 5的搜索共返回了32个超冷亚矮星候选者，只有两个在文献中被认为是亚矮星。在600和1000 nm之间的光学范围内对27个候选物进行了光谱跟踪。我们确认了20颗光谱类型晚于M5的次矮星、极端次矮星或超次矮星，成功率约为60%。在这20个新的次矮星中，我们发现了2个早期的L次矮星，它们很可能位于100 pc以内，我们建议将它们作为未来搜索的模板，因为它们是它们子类的第一个例子。另外7个源是太阳金属丰度M矮星，光谱类型在M4和M7之间，没有H α发射，表明它们是古老的M矮星。剩下的5颗候选星还没有后续的光谱观测，只有1颗在修正了自行后仍然是真正的超冷亚矮星。我们根据当前的分类方案分配光谱类型，并在可能的情况下测量它们的径向速度。利用有限数量的具有三角形半径的次矮星，我们估计新的次矮星的距离在90到600之间。我们提供了两颗亚矮星的WISE中红外测光结果，并讨论了它们的颜色。最后，我们估计了超冷次矮星表面密度的下限，其数量级比太阳金属丰…
