发表机构
Memorial University of Newfoundland; East Tennessee State University（纽芬兰纪念大学; 东田纳西州立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用VStar分析5颗长周期变星光变曲线，发现V CVn存在超长次级周期，并通过MESA和GYRE构建模型检验交叉谐波假说，结果表明该假说无法解释LSP现象。
AI 中文摘要
长周期变星（LPVs）是周期超过100天的渐近巨星分支恒星。大约三分之一到一半的LPVs显示出长次级周期（LSP），其长度是主周期的5-10倍。LSP的确切成因尚不清楚，一个可能的解释在于两个同时发生的周期相互作用产生的交叉谐波。在本文中，我们使用傅里叶分析软件VStar来检查通过美国变星观测者协会获得的5颗恒星样本的可见光波段测光光变曲线。我们发现其中一颗恒星V CVn显示出超过其主周期20倍的次级周期，这与传统的LSP不一致。为了测试交叉谐波是否可能导致LSP或V CVn的超长次级周期，我们随后使用恒星演化模块（MESA）和GYRE构建了LPVs的演化轨迹和脉动模型。在检查了基频脉动模式与前4个泛音之间的相互作用后，我们没有发现证据表明LSP或V CVn的超长次级周期可能是由交叉谐波引起的。
英文摘要
Long Period Variables (LPVs) are Asymptotic Giant Branch stars with periods >100 days. Around one third to half of LPVs display a Long Secondary Period (LSP) that is 5-10 times the length of the main periods. The exact cause of LSPs are unknown, with one potential explanation lying in cross-harmonics caused by the interaction of two simultaneously occurring periods. In this paper, we use the Fourier analysis software VStar to examine the visual range photometric light curves obtained through the American Association of Variable Star Observers of a sample of 5 stars. We find that one star, V CVn, displays a secondary period over 20 times the length of its main period, inconsistent with traditional LSPs. To test if cross-harmonics can result in an LSP or VCVn's extra-long secondary period, we then construct evolutionary tracks and pulsation models of LPVs using Modules for Evolution in Stellar Astrophysics (MESA) and GYRE. After examining the interactions of the fundamental pulsation mode and the first 4 overtones with each other, we do not find evidence that LSPs or V CVn's extra-long secondary period could be caused by cross-harmonics.
Comments12 pages, 19 figures; Submitted to AAS; Comments welcome
