We present results of a study of the Na I D interstellar absorption toward 17 binary and/or common proper-motion systems (including two triples). The stars range in spectral type from O6 to A5, lie at distances between 85 and 1200 pc, and have stellar separations between 480 and 29,000 AU. We compare the Na I absorption present in each of the two (or three) lines of sight and find that the line strength and/or profile varies for all 17 of the systems examined. We infer that small-scale structure in clouds containing Na I is ubiquitous and discuss the implications of that conclusion.
展开▼
机译：我们提出了Na I D星际吸收对17个二元和/或普通固有运动系统（包括两个三元组）的研究结果。这些恒星的光谱类型范围从O6到A5，位于85至1200 pc之间的距离，并且恒星间隔在480至29,000 AU之间。我们比较了两个（或三个）视线中每个视线中存在的Na I吸收量，发现对于所检查的所有17个系统，其线强度和/或轮廓均发生变化。我们推断包含Na I的云中的小规模结构无处不在，并讨论该结论的含义。
展开▼
