论文标题
母鸡的演变，3-1357，黄貂鱼星云
Evolution of Hen\,3-1357, the Stingray Nebula
论文作者
论文摘要
亨\，3-1357的光谱进化是黄貂鱼星云，通过分析1990年至2021年的数据来提出。2021年获得的高分辨率数据与南非大型望远镜高分辨率光谱仪以及2009年在2009年与欧洲南部观测值远端望远镜uves upe仪的适用于物理条件和化学量相适应的欧洲南部观测值。从这些数据与来自不同时期的数据的比较中可以发现，高度离子发射线的强度随着时间的流逝而减少，而低离子线的排放量正在增加，证实了在2002年中心恒星中，在2002年有效温度下来的核心恒星的结果是，它在2002年的变化中降低了它的激发阶段，从而降低了它的激励阶层。中央恒星的当前有效温度约为40,000K。有人建议中央恒星遭受了晚期的热脉冲，并且正在恢复到AGB相。 Hen \，3-1357的Nebular化学表明，除HE和NE以外的所有元素都具有亚太阳丰度。在AGB阶段结束时，恒星核合成模型预测的Nebular丰度与值的值的比较表明，中心恒星的初始质量低于1.5 m $ _ {\ odot} $。我们估计ADF（O $^{+2} $）在2.6和3.5之间。
The spectroscopic evolution of Hen\,3-1357, the Stingray Nebula, is presented by analysing data from 1990 to 2021. High resolution data obtained in 2021 with South African Large Telescope High Resolution Spectrograph and in 2009 with European Southern Observatory-Very Large Telescope UVES spectrograph are used to determine physical conditions and chemical abundances in the nebula. From comparison of these data with data from different epochs it is found that the intensity of highly-ionized emission lines has been decreasing with time, while the emission of low-ionization lines has been increasing, confirming that the nebula is recombining, lowering its excitation class, as a consequence of the changes in the central star which in 2002 had an effective temperature of 60,000 K and from then it has been getting colder. The present effective temperature of the central star is about 40,000 K. It has been suggested that the central star has suffered a late thermal pulse and it is returning to the AGB phase. The nebular chemistry of Hen\,3-1357 indicates that all the elements, except He and Ne, present sub solar abundances. The comparison of the nebular abundances with the values predicted by stellar nucleosynthesis models at the end of the AGB phase, shows that the central star had an initial mass lower than 1.5 M$_{\odot}$. We estimated the ADF(O$^{+2}$) to be between 2.6 and 3.5.
