论文标题
锂中的非紧密恒星中的锂
Lithium in coalesced non-compact stars
论文作者
论文摘要
语境。银河红novae被认为是在非紧凑型恒星（例如主序列恒星和凉爽巨人）之间出现的恒星合并中产生的。他们希望有助于解释共同的信封进化和出色的二元碰撞中涉及的物理过程。目标。我们研究了三个最佳的银河红色新星残留物中锂的存在。解释锂的起源可能指向合并之前，之中或之后存在的混合机制。方法。将6707.81 A处的锂线与[Ca I时6572.78 A的特征与偶尔气中的相对丰度相比。假设太阳钙与锂丰度比，则接下来计算绝对丰度。结果。在V838 MON的合并残余物中测量了锂丰度，a（li）= 2.3，ck vul，a（li）= 2.5和v1309 SCO，a（li）= 1.8。结论。锂在红色Novae中过多，表明至少有些合并产品激活了Cameron-Fowler机制，从而使对流混合可以到达深层恒星内部。无论是深层对流和相关的扩散还是其他一些过程（例如，旋转）都可能导致驱动卡梅隆 - 福克机制在残余物中需要进一步的研究。在V838 Mon中对锂的早期观察表明，这些机制可以早期激活，也许已经处于共同的包膜阶段。在对这些复杂系统进行建模时，应考虑这些观察结果。
Context. Galactic red novae are thought to be produced in stellar mergers between non-compact stars, such as main-sequence stars and cool giants. They are hoped to help in explaining physical processes involved in common envelope evolution and stellar binary collisions. Aims. We investigate the presence of lithium in three best-observed Galactic red nova remnants. Explaining the origin of lithium may point to mixing mechanism present before, during, or after the merger. Methods. The lithium line at 6707.81 A was compared to a feature of [Ca I at 6572.78 A to derive relative abundances in circumstellar gas. Absolute abundances were next calculated assuming the Solar calcium to lithium abundance ratio. Results. Lithium abundances were measured in the merger remnants of V838 Mon with A(Li)=2.3, CK Vul with A(Li)=2.5, and V1309 Sco with A(Li)=1.8. Conclusions. Lithium is overabundant in red novae, suggesting that at least some merger products activate the Cameron-Fowler mechanism whereby convective mixing can reach the deep stellar interior. Whether deep convection and associated diffusion alone or some other processes (e.g. spin down) can be responsible for driving the Cameron-Fowler mechanism in the remnants requires further studies. Early observations of lithium in V838 Mon hint that these mechanisms can activate early, perhaps already in the common envelope phase. These observations should be taken into account in modelling these complex systems.
