Collaborative Research: Confirming and Characterizing Transiting Exoplanets around Bright Stars with Ultra-precise Ground-based Photometry

今天，许多太阳系外行星(“系外行星”)都是通过精确跟踪它们所围绕的恒星发出的光而被发现的。当行星经过恒星或从恒星前面经过时，恒星的一小部分光线会被阻挡。这使得天文学家能够确定这颗行星的许多性质。PI的团队是使用一种名为工程漫射器的光学设备的先驱。这种装置大大减少了恒星光输出的不确定度来源，特别是被称为闪烁(外行术语中的“闪烁”)的效应。他们将使用这项技术来识别、确认和研究围绕明亮恒星的小至地球大小的行星。他们还将使用这项技术，通过探测恒星表面类似太阳黑子的黑子来研究恒星的磁场。本科生和研究生以及一名博士后助理将参加观察和数据分析。合作者还将把这些成果纳入他们所在机构的教学和公共宣传中。由于昼夜循环、大气效应、闪烁、透明度变化、差异消光、能见度和望远镜导引效应，基于地面的观测在精度上受到一些限制，这些因素通常会阻碍它们达到天基任务的光度精度。小口径望远镜提供的较大视场使明亮的比较星更容易被发现，然而，上述挑战往往阻碍小望远镜与天基测光精度相匹配。更大的望远镜可以提供更好的闪烁平均值。该小组在地面实施的漫射器辅助测光提供了与散焦小型望远镜相比的性能改进，他们已经展示了与太空望远镜相媲美的空中测光性能，成本只有太空望远镜的一小部分。这一奖项反映了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。

Many extra-solar planets ("exoplanets") are discovered today by tracking precisely the light from the star they orbit. When the planet transits, or passes in front of, the star, a tiny bit of the star's light is blocked. This allows astronomers to determine many properties of the planet. The PI's team are pioneers in using an optical device called an Engineered Diffuser. This device significantly reduces sources of uncertainty in the light output of the star, especially the effect known as scintillation ("twinkling," in a layperson's term). They will use this technique to identify, confirm, and study planets down to Earth's size around bright stars. They will also use the technique to study the stars' magnetic fields by detecting spots analogous to sunspots on the surface of the stars. Undergraduate and graduate students, and a postdoctoral associate, will take part in the observations and data analysis. The collaborators will also incorporate the results into their teaching and public outreach at their institutions.Ground-based observations are subject to a number of limitations in their precision due to the day-night cycle, atmospheric effects, scintillation, transparency variations, differential extinction, seeing, and telescope-guiding effects which typically prevents them from achieving the photometric precision of space-based missions. The larger field of view offered by small aperture telescopes enables bright comparison stars to be more readily found, however, the aforementioned challenges often prevent small telescopes from matching space-based photometric precision. Larger telescopes offer better averaging of scintillation. The group's implementation of diffuser-aided photometry from the ground provides an improvement in performance compared to de-focused small telescopes and they have demonstrated on-sky photometric performance that rivals that of space telescopes at a fraction of the cost.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.