A Leap in Sensitivity for CHARA/CLASSIC Optical Interferometry for Astronomy

光学干涉测量法使用一组连接在一起的较小望远镜，以实现数百米宽的望远镜的角分辨率。 这种干涉仪具有极大望远镜的分辨率，但具有小型望远镜的灵敏度。他们可以看到非常细致的星星，但到目前为止只能看到相对明亮的星星。该项目的主要目标是提高位于威尔逊山天文台的高角分辨率天文学中心（CHARA）阵列干涉仪的灵敏度。对相机、光学玻璃和数据记录的改造将使研究恒星的亮度比目前可能的暗10倍。这种提高的灵敏度将使研究能够了解宇宙中其他地方是否存在生命，并开辟新的研究领域。该计划还将包括在每年接待15，000名游客的CHARA游客中心的新设施，以及与美国自然历史博物馆合作，在CHARA游客中心展示当前的科学公告。CHARA阵列最长基线产生的角直径测量值在K波段为0.7 mas，在R波段为0.2 mas。CHARA可以分辨出所有沿着O型到M型的主序星盘，而下一代单孔径望远镜将无法分辨主序星。地基干涉测量中最重要的问题是灵敏度。该计划将在近红外范围内将CLASSIC/CLIMB光束组合器的限制提高2个数量级。这将通过用现代化的基于SELEX MOVPE SAPHIRA的检测系统取代已有20年历史的PICNIC检测器来实现。这次升级还将包括H和K波段的光谱分辨率，两个波段的同时观测以及偏振分离。随着灵敏度的提高，将有可能调查更广泛的恒星直径和温度，年轻恒星周围的圆盘，大质量恒星的风，相互作用和分离的双星，瞬态事件，以及通过NSF/MSIP资助的社区访问计划为客座观察员开辟新的机会。更高的灵敏度也将极大地扩展观测活动星系核（AGN）核心的能力。CHARA首次能够直接确认或否定AGN核心的二元结构。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。

Optical interferometry uses an array of smaller telescopes connected together to achieve the angular resolution of telescopes many hundreds of meters across. Such interferometers have the resolution of extremely large telescopes but have the sensitivity of small telescopes. They can see stars in exquisite detail but can so far only see relatively bright stars. The main goal of this project is to improve the sensitivity of one of these interferometers called the Center for High Angular Resolution Astronomy (CHARA) Array, which is located at Mount Wilson Observatory. Renovations to the camera, optical glass, and data recording will enable studying stars 10 times fainter than currently possible. Such improved sensitivity will enable investigations that may inform whether life may exist elsewhere in the universe, and open up new areas of research. This program will also include new facilities in the CHARA visitor center, which hosts 15,000 visitors each year, and a collaboration with the American Museum of Natural History to display current science bulletins at the CHARA visitor center.The CHARA Array longest baseline yields angular diameter measurements as small as 0.7 mas in K band improving to 0.2 mas at R. CHARA can resolve stellar disks all along the main sequence from O- to M-types, whereas there will be no main sequence stars resolvable by the next generation of single aperture telescopes. The most significant problem in ground based interferometry is sensitivity. This program will increase the limit of the CLASSIC/CLIMB beam combiner by 2 magnitudes in the near infrared. This will be achieved by replacing the 20-year-old PICNIC detector with a modern SELEX MOVPE SAPHIRA based detection system. This upgrade will also include spectral resolution in both H and K bands, simultaneous observation in both bands, and a polarization split. With enhanced sensitivity it will be possible to survey a much broader range of stellar diameters and temperatures, the disks around young stars, winds from massive stars, interacting and detached binary stars, transient events, as well as open up new opportunities for guest observers through the community access program funded by NSF/MSIP. More sensitivity will also vastly expand the ability to observe the cores of Active Galactic Nuclei (AGN). The CHARA could directly confirm or deny a binary structure in an AGN core for the first time.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.