Development of environment-controlled enclosures for the Network of Robotic Echelle Spectrographs

就在几十年前，科学家们发现了第一批围绕其他恒星运行的行星。从那时起，很明显，这些“系外行星”在宇宙中非常普遍，并且已经编制了大量的目录。详细的后续研究通常是困难的，因为它们的光线很微弱，但对于理解系外行星以及它们对一系列推理的贡献至关重要，这些推理最终关系到宇宙中其他地方生命本身有多普遍的问题。一旦发现系外行星，就需要非常专业的仪器来彻底研究它们，而仪器的短缺是拉斯康布雷斯天文台全球望远镜（LCOGT）建设的一个重大瓶颈。LCOGT是一个主要由1米望远镜组成的全球网络。LCOGT将通过美国国家科学基金会最近的资助，配备适合于系外行星研究的精确光谱仪。目前的提案以更好的外壳形式解决了仪器的改进，该外壳将被热控制，以实现最佳的光谱精度。要构建的原型将展示整个系统性能中的一个重要元素。LCOGT项目解决了ASTRO 2010（十年）报告的一个具体建议，该报告呼吁增加望远镜时间用于径向速度（RV）系外行星的工作，即使限制精度没有从当时的水平提高。LCOGT将使全国范围内对系外行星进行RV研究的能力大约增加一倍，并将使比V=12亮的恒星在不到一小时的曝光时间内达到3米/秒的精度。凭借其多个位置，LCOGT提供了数据采集数量和质量的强大组合。最终的LCOGT光谱仪是交叉分散梯队，分辨率R=53,000，几乎覆盖380-860 nm的全波长，旨在提高效率，稳定性和易于波长校准。新的外壳设计被称为“冰屋”，经过精心隔热和温度控制。3米/秒的RV精度要求温度控制在+/- 1摄氏度。NRES系统将使天文学家能够表征系外行星候选宿主恒星，验证过境伴星，搜索多行星系统，并获得大范围行星的质量和轨道元素。候选者将由地面过境调查提供，如HATnet、SuperWASP和卡塔尔，以及美国宇航局的TESS任务。LCOGT项目在教育方面很活跃，开展了一个广泛的项目，让学生用望远镜进行观测。从高中到大学四年级的许多学生都被聘为实习生。为LCOGT开发的设计是开源的，科学数据也向社区提供。该项目由美国国家科学基金会天文科学部通过其先进技术和仪器计划提供资金。

Just a few decades ago, scientists discovered the first planets around other stars. Since then, it has become apparent that these "exoplanets" are very common in the universe, and a large catalog of them has been compiled. Detailed followup study is generally difficult, owing to the faintness of their light, but is vital to understanding the exoplanets and their contribution to a chain of reasoning that ultimately bears on the question of how common life itself might be elsewhere in the universe. Very specialized instrumentation is needed to study exoplanets thoroughly once they are detected, and the shortage of that instrumentation is a significant bottleneck addressed by the construction of the Las Cumbres Observatory Global Telescope (LCOGT), a worldwide network of primarily 1-meter telescopes. LCOGT will be equipped, through recent NSF funding, with precise spectrographs appropriate to exoplanet study. The current proposal addresses an improvement to the instrumentation in the form of a better enclosure that will be thermally controlled to allow optimum spectrographic precision to be achieved. The prototype to be constructed will demonstrate an important element in overall system performance.The LCOGT project addresses a specific recommendation of the ASTRO 2010 (decadal) report calling for making increased telescope time available to radial velocity (RV) exoplanet work, even if limiting precision were not improved from then-current levels. LCOGT will roughly double the nationwide capacity for RV studies of exoplanets, and will allow accuracy of 3m/s in exposure times of less that an hour for stars brighter than V=12. With its multiple locations, LCOGT provides a powerful combination of quantity and quality of data acquisition. The ultimate LCOGT spectrographs are cross-dispersed echelles with resolving power R=53,000 and almost full wavelength coverage over 380-860 nm, designed for efficiency, stability, and ease of wavelength calibration. The new enclosure design is called an "igloo", and is carefully insulated and temperature-controlled. An RV accuracy of 3 m/s requires temperature control to +/- 1 C. The NRES system will enable astronomers to characterize exoplanet candidate host stars, validate transiting companions, search for multiple planetary systems, and derive masses and orbital elements for a wide range of planets. Candidates will be supplied by ground-based transit surveys, such as HATnet, SuperWASP, and Qatar, and from NASA's TESS mission.The LCOGT project is active in education, operating an extensive program of student observing on their telescopes. Numerous students from high-school to university seniors are employed as interns. Designs developed for LCOGT are open-source, and science data are made available to the community.Funding for this project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.