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”）是通过精确跟踪它们所围绕的星星发出的光而被发现的。当这颗行星经过或经过星星的前面时，星星发出的一小部分光被阻挡了。这使天文学家能够确定行星的许多属性。PI的团队是使用一种称为工程漫射器的光学设备的先驱。这种装置显著地减少了星星光输出的不确定性来源，特别是被称为闪烁（外行术语中的“闪烁”）的效应。他们将使用这种技术来识别，确认和研究明亮恒星周围的行星，这些行星的大小可以达到地球的大小。他们还将使用该技术通过探测恒星表面类似太阳黑子的斑点来研究恒星的磁场。本科生和研究生以及博士后助理将参加观察和数据分析。由于昼夜周期、大气效应、闪烁、透明度变化、差异消光、视宁度和望远镜制导效应，地面观测的精度受到一些限制，这通常使它们无法达到天基任务的光度精度。小口径望远镜提供的更大视野使明亮的比较星更容易被发现，然而，上述挑战往往使小望远镜无法达到天基测光精度。更大的望远镜提供更好的闪烁平均。与散焦的小型望远镜相比，该小组从地面实施的漫射器辅助测光提供了性能上的改进，并且他们已经证明了在天空中的测光性能可以与空间望远镜相媲美，成本仅为空间望远镜的一小部分。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值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.