标题： PM 1-188的二十年观测：化学丰度与非凡动力学 显示英文标题

标题： Twenty years of observations of PM 1-188: Its chemical abundances and extraordinary kinematics

摘要： 展示了PM 1-188双壳行星状星云20年的光度测定数据的分析，目的是确定发射线的时间演化及其星云的物理条件，这是由于其[WC 10]中心恒星系统的逐渐变暗所致，该恒星在过去40年中亮度下降了约10个星等。 我们的主要结果包括：由于电子温度从2005年的11,000 K增加到2018年的超过14,000 K（由冲击波引起），内层星云中的[\ion{O}{iii}]、[\ion{O}{ii}]、[\ion{N}{ii}]线强度随时间增加。 同一时期，外层星云中的这些线强度由于温度从13,000 K降至7,000 K而减少。 推导出了内外壳的化学成分，它们是相似的。 两个星云都显示出次太阳O、S和Ar丰度，同时它们富含He、N和Ne。 对于外部星云，He/H 的值为 12+log He/H=11.13$\pm$0.05，O/H 的值为 12+log O/H=8.04$\pm$0.04，N/H 的值为 12+log N/H=7.87$\pm$0.06，S/H 的值为 12+log S/H=7.18$\pm$0.10，而 Ar 的值为 12+log Ar=5.33$\pm$0.16。 氧、硫和氩的丰度比盘状非I型PNe中的平均值低数倍，并且与一些晕轮PNe相似。 从高分辨率光谱中，在内区发现了一个南北方向的外流。 位置-速度图显示，外流以每秒150到100公里的 velocity$-$$^{-1}$范围内的速度膨胀，且两个壳层的膨胀速度均为约每秒40公里 velocity$^{-1}$。 显示英文摘要

摘要： The analysis of 20 years of spectrophotometric data of the double shell planetary nebula PM\,1-188 is presented, aiming to determine the time evolution of the emission lines and the physical conditions of the nebula, as a consequence of the systematic fading of its [WC\,10] central star whose brightness has declined by about 10 mag in the past 40 years. Our main results include that the [\ion{O}{iii}], [\ion{O}{ii}], [\ion{N}{ii}] line intensities are increasing with time in the inner nebula as a consequence of an increase in electron temperature from 11,000 K in 2005 to more than 14,000 K in 2018, due to shocks. The intensity of the same lines are decreasing in the outer nebula, due to a decrease in temperature, from 13,000 K to 7,000 K, in the same period. The chemical composition of the inner and outer shells was derived and they are similar. Both nebulae present subsolar O, S and Ar abundances, while they are He, N and Ne rich. For the outer nebula the values are 12+log He/H= 11.13$\pm$0.05, 12+log O/H = 8.04$\pm$0.04, 12+log N/H= 7.87$\pm$0.06, 12+log S/H = 7.18$\pm$0.10 and 12+log Ar = 5.33$\pm$0.16. The O, S and Ar abundances are several times lower than the average values found in disc non-Type I PNe, and are reminiscent of some halo PNe. From high resolution spectra, an outflow in the N-S direction was found in the inner zone. Position-velocity diagrams show that the outflow expands at velocities in the $-$150 to 100 km s$^{-1}$ range, and both shells have expansion velocities of about 40 km s$^{-1}$.