狮子座ρ星的十年径向速度监测：矩分析与周期性变异性
A decade of radial-velocity monitoring of rho Leo: moment analysis and periodic variability
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中文总结 AI 辅助
本研究通过对狮子座ρ星11.5年的光谱与TESS等数据进行矩分析，检测到16.46天的稳定周期信号，推测其源于非径向脉动，同时指出需区分双星起源的可能性。
中文摘要 AI 辅助
我们研究蓝超巨星狮子座ρ星长期光谱与光度变异性的起源，重点区分其本征脉动与可能伴星引发的变异性。分析基于塔尔图天文台获取的11.5年光谱时间序列，辅以Hertzsprung SONG望远镜的高采样率高分辨率光谱，以及TESS空间光度测量数据。我们利用He I 6678、He I 5875和Si III 4552谱线的归一化矩研究线轮廓变异性，通过带迭代预 whitening 的广义 Lomb-Scargle 周期图识别周期信号，并用加权小波Z变换检验其时序稳定性。我们在第一和第三矩中检测到持续的周期信号，周期P=16.46天，在整个观测区间内均存在，其径向速度振幅为3.9 km/s；该信号也出现在SONG数据中，且可见于多条谱线，表明具有全局起源。光度观测显示主导变时标约为33天，约为光谱周期的两倍。该稳定的16.46天周期存在于整个观测区间，极可能源于超巨星的非径向脉动；不排除该信号来自双星起源，但超巨星复杂的变异性模式使区分这些情形变得复杂。
英文摘要
We investigate the origin of long-term spectroscopic and photometric variability in the blue supergiant rho Leo, with particular emphasis on distinguishing between intrinsic pulsations and variability induced by a possible companion. Our analysis is based on an 11.5-year spectroscopic time series obtained at Tartu Observatory, complemented by high-cadence, high-resolution spectroscopy from the Hertzsprung SONG telescope and space-based photometry from TESS. We studied line-profile variability using normalised moments of the HeI 6678, HeI 5875, and SiIII 4552 lines. Periodic signals were identified using the generalised Lomb-Scargle periodogram with iterative pre-whitening, and their temporal stability was examined with the weighted wavelet Z-transform. We detect a persistent periodic signal at P = 16.46 d in the first and third moments, present throughout the full observing interval, with a radial-velocity amplitude of 3.9 km/s. This signal is also present in the SONG data and is visible in multiple spectral lines, indicating a global origin. Photometric observations reveal a dominant variability timescale near 33 d, approximately twice the spectroscopic period. The stable 16.46-day period, present throughout the entire observing interval, most likely results from non-radial pulsations of the supergiant. A binary origin of the signal is not excluded, but distinguishing between these scenarios is complicated by the supergiant's complex variability pattern.
