Discovering the First Exoplanets Around White Dwarf Stars with the Zwicky Transient Facility

基顿·贝尔被授予美国国家科学基金会天文学和天体物理学博士后奖学金，负责华盛顿大学的一项研究和教育项目。他将利用兹维基瞬变设施(ZTF)的数据，试图首次发现围绕白矮星运行的太阳系外行星(系外行星)-坍塌的恒星，这些恒星不再像正常恒星那样从核聚变中产生能量，而是从残热中发出微弱的光芒。贝尔将确定有多少WD系外行星存在，并研究WD系外行星的数量，这将使他更好地理解行星系统如何在恒星坍塌后幸存下来。结合他的研究，他将指导科学、技术、工程和数学(STEM)领域中代表性较低的群体的大学新生，并帮助培训天文学研究生数据科学的方法。这项拟议的科学计划旨在描述单个WD行星系统的特性，并研究在主序列后演化过程中影响行星的物理机制。贝尔建议通过在ZTF数据集中搜索测量到的通量的统计显著下降来识别候选行星凌日。强有力的候选者将通过后续的光度和光谱观察来确认和表征。他工作的教育部分将通过为学生提供宝贵的技能，为可能的科学或工程职业生涯做准备，帮助促进更有能力和多样化的STEM员工队伍。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Keaton Bell is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to conduct a program of research and education at the University of Washington. He will use data from the Zwicky Transient Facility (ZTF) to attempt to make the first discoveries of extrasolar planets (exoplanets) orbiting white dwarf (WD) stars --- collapsed stars, which are no longer producing energy from nuclear fusion like normal stars, but are glowing faintly from residual heat. Bell will determine what fraction of WDs host exoplanets, and study the populations of WD exoplanets, which will lead him to a better understanding of how planetary systems survive the collapse of their star. In conjunction with his research, he will mentor college freshman students from groups underrepresented in science, technology, engineering, and mathematics (STEM) fields, and he will help train astronomy graduate students in methods of data science. The proposed scientific program seeks to characterize the properties of individual WD planetary systems and investigate the physical mechanisms that affect planets during post-main-sequence evolution. Bell proposes to identify candidate planet transits by searching the ZTF data set for statistically significant dips in measured flux. Strong candidates will be confirmed and characterized with follow-up photometric and spectroscopic observations. The educational component of his work will help promote a more capable and diverse STEM workforce by providing students with valuable skills in preparation for possible careers in science or engineering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.