标题： 富碳渐近巨星分支星周围的不对称尘埃案例 显示英文标题

标题： The Case for Asymmetric Dust Around a C-Rich AGB star

摘要： 给出了关于质量损失的碳Mira变星IRAS 15194-5115（II Lup）在约18年的JHKL观测，并进行了讨论。 脉动周期为575天，在此时间段内基本保持恒定。 在此期间，该恒星经历了一次广泛的掩食极小值。 这很复杂，且与类似天体中的此类极小值（例如R For）一样，不符合简单长期周期性的模型预测。 结合Lopez等人提供的高分辨率观测结果，这些结果表明，掩食的变化可能是由于视线方向上有限范围尘埃云的形成所致。 这是一种RCB型模型。 在J和H波段的有效消光定律与R For所发现的类似。 显示英文摘要

摘要： JHKL observations of the mass-losing carbon Mira variable IRAS 15194-5115 (II Lup) extending over about 18 years are presented and discussed. The pulsation period is 575 days and has remained essentially constant over this time span. The star has undergone an extensive obscuration minimum during this time. This is complex and, like such minima in similar objects, e.g. R For, does not fit the model predictions of a simple long term periodicity. Together with the high resolution observations of Lopez et al. the results suggest that the obscuration changes are due to the formation of dust clouds of limited extent in the line-of-sight. This is an RCB-type model. The effective reddening law at J and H is similar to that found for R For.