AI 中文总结
本研究利用TESS数据，通过500pc内20-9亿年的疏散星团，发现δ Scuti脉动星出现率随年龄降低，快速自转对维持其脉动关键，还明确了温度与脉动停止的关联。
AI 中文摘要
许多A型和F型恒星虽位于不稳定带内，却未表现出δ Scuti型脉动。我们利用凌日系外行星巡天卫星（TESS任务）的测光数据，在距离500秒差距内、年龄约20至9亿年的疏散星团中发现并研究δ Scuti型脉动星，这类星团为研究同年龄、化学组成均匀的δ Scuti型脉动星提供了独特机会。我们对所有星团测量了经完整性校正的脉动星出现率。研究发现，年龄小于2亿年的星团往往表现出更高的出现率，平均出现率为88±3%；年龄大于2亿年的星团的出现率则更接近场星样本的脉动星占比，平均出现率为62±3%。此外，我们发现较老星团中的脉动星往往比年轻星团中的脉动星自转更快，且温度更高的脉动星可能比温度更低的脉动星更早停止脉动。这些结果表明，δ Scuti型脉动星的出现率随年龄增长而降低，快速自转对维持δ Scuti型脉动随时间持续存在至关重要。
英文摘要
Many A- and F- type stars do not display $δ$ Scuti pulsations, despite being located within the instability strip. We use photometry from the TESS Mission to discover and study $δ$ Scuti pulsators in open clusters within 500 pc and with ages between ~20 and 900 Myr, which provide a unique opportunity to study $δ$ Scuti pulsators in coeval populations with uniform chemical composition. We measure pulsator occurrence, which corrects the pulsator fraction for incompleteness, across all clusters. We find that clusters younger than 200 Myr tend to exhibit higher occurrence rates, with an average occurrence of 88$\pm$3\%. The occurrence rates in clusters older than 200 Myr tend to resemble the pulsator fraction of field-star samples, with an average occurrence of 62$\pm$3\%. In addition, we find that pulsators tend to rotate more rapidly in older clusters than their younger counterparts and that hotter pulsators may stop pulsating earlier than their cooler counterparts. These results show that pulsator occurrence decreases with age and that rapid rotation is critical in maintaining $δ$ Scuti pulsations over time.
CommentsAccepted for publication in ApJ. 17 pages, 10 Figures, 2 Tables
