TESS Cycle 2 observations of roAp stars with 2-min cadence data
TESS Cycle 2 observations of roAp stars with 2-min cadence data
复制标题
使用 2 分钟节奏数据对 roAp 恒星进行 TESS 周期 2 观测
DOI：
10.1093/mnras/stad3800
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发表时间：
2024
影响因子：
4.8
通讯作者：
Holdsworth D
中科院分区：
文献类型：
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作者：
Holdsworth D
我们提出了对凌日系外行星勘测卫星 (TESS) 2 分钟节奏数据进行系统搜索的结果，以查找在其任务的 Cycle 2 阶段观测到的新的快速振荡 Ap (roAp) 恒星。我们发现了 7 颗以前未曾报道过的新 roAp 恒星，并对另外 25 颗已知的 roAp 恒星进行了分析。其中三颗新恒星显示出多周期脉动，而所有新成员都是旋转变星，导致几乎 70%（22）的 roAp 恒星是 α2CVn 型变星。我们表明，对已知化学奇特恒星的有针对性的观测可能会忽略许多新的 roAp 恒星，并证明多历元观测对于观察脉动行为的变化是必要的。我们发现靠近理论 roAp 不稳定带的蓝色边缘缺乏 roAp 恒星，并重申通过精确的天基观测更频繁地观察到模式不稳定。除了 Cycle 2 观测之外，我们还分析了所有已知 roAp 恒星的 TESS 数据。这相当于 TESS 观测到的另外 18 颗 roAp 星。最后，我们列出了 TESS 尚未观测到的六颗已知的 roAp 恒星。我们推断，roAp 星在 Ap 星族中的发生率仅为 5.5%，这引发了有关激发 Ap 星脉动所需条件的基本问题。这项工作与我们之前在 Cycle 1 观测中对 roAp 星的工作相结合，提出了对 TESSnominal 任务中 roAp 星最全面、同质的研究，总共收集了 112 颗已确认的 roAp 星。
We present the results of a systematic search of theTransiting Exoplanet Survey Satellite(TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the Cycle 2 phase of its mission. We find seven new roAp stars previously unreported as such and present the analysis of a further 25 roAp stars that are already known. Three of the new stars show multiperiodic pulsations, while all new members are rotationally variable stars, leading to almost 70 per cent (22) of the roAp stars presented being α2CVn-type variable stars. We show that targeted observations of known chemically peculiar stars are likely to overlook many new roAp stars, and demonstrate that multiepoch observations are necessary to see pulsational behaviour changes. We find a lack of roAp stars close to the blue edge of the theoretical roAp instability strip, and reaffirm that mode instability is observed more frequently with precise, space-based observations. In addition to the Cycle 2 observations, we analyseTESSdata for all-known roAp stars. This amounts to 18 further roAp stars observed byTESS. Finally, we list six known roAp stars thatTESSis yet to observe. We deduce that the incidence of roAp stars amongst the Ap star population is just 5.5 per cent, raising fundamental questions about the conditions required to excite pulsations in Ap stars. This work, coupled with our previous work on roAp stars in Cycle 1 observations, presents the most comprehensive, homogeneous study of the roAp stars in theTESSnominal mission, with a collection of 112 confirmed roAp stars in total.