近邻宜居行星巡天计划:利用空间天体测量法寻找下一个“地球”  

Closeby Habitable Exoplanet Survey(CHES):an Astrometry Mission for Probing Nearby Habitable Planets

作　　者：季江徽[1,2,3] 李海涛 张俊波 李东[8] 方亮 王素 邓雷[8] 陈果 李飞[8] 董瑶 李保权 高晓东[6] 鲜浩 JI Jianghui;LI Haitao;ZHANG Junbo;LI Dong;FANG Liang;WANG Su;DENG Lei;CHEN Guo;LI Fei;DONG Yao;LI Baoquan;GAO Xiaodong;XIAN Hao(Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026;Key Laboratory of Planetary Sciences,Chinese Academy of Sciences,Nanjing 210023;National Space Science Center,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049;Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209;National Laboratory on Adaptive Optics,Chinese Academy of Sciences,Chengdu 610209;Innovation Academy for Microsatellites,Chinese Academy of Sciences,Shanghai 201306)

机构地区：[1]中国科学院紫金山天文台,南京210023 [2]中国科学技术大学天文与空间科学学院,合肥230026 [3]中国科学院行星科学重点实验室,南京210023 [4]中国科学院国家空间科学中心,北京100190 [5]中国科学院大学,北京100049 [6]中国科学院光电技术研究所,成都610209 [7]自适应光学全国重点实验室,成都610209 [8]中国科学院微小卫星创新研究院,上海201306

出　　处：《空间科学学报》2024年第2期193-214,共22页Chinese Journal of Space Science

基　　金：中国科学院空间科学战略性先导科技专项(二期)背景型号项目(XDA 15020800);国家自然科学基金项目(12033010,12073084,12150009);紫金山天文台小行星基金会项目共同资助。

摘　　要：近邻宜居行星巡天计划(Closeby Habitable Exoplanet Survey,CHES)采用空间微角秒级别的高精度天体测量技术,普查太阳系近邻(10 pc内)约100颗FGK等类型恒星,探测宜居带类地行星或超级地球;详细普查宜居行星的数目、真实质量和三维轨道等信息,这将是国际上首次近邻宜居带类地行星的空间探测任务.CHES的有效载荷是一台口径为1.2 m,视场为0.44°×0.44°,焦距为36 m的高像质、低畸变、高稳定光学望远镜,采用同轴三反TMA光学成像系统.为实现宜居带类地行星探测,CHES任务中的测量精度为1μas,是目前国际测量精度最高的空间探测项目.在空间科学先导专项背景型号项目的支持下,CHES团队深入凝练和论证科学目标,成功突破了三项关键技术难题:实现了畸变大视场高像质空间望远镜光学系统技术的重要突破;突破了10–5 pixel级别星间距测量技术;实现了卫星系统高稳定度姿态控制精度及热控精度的创新.CHES预计发现50颗类地行星,引领中国空间科学探测技术的跨越式发展.The Closeby Habitable Exoplanet Survey(CHES)employs state-of-the-art,high-precision astrometry and positioning technology at the microarcsecond level in space.Its primary objective is to conduct a thorough survey of approximately 100 FGK-type stars within the Sun’s proximity(within 10 parsecs),with the goal of detecting potentially habitable Earth-like planets or super-Earths.This pio-neering mission involves a detailed census of habitable planets,providing intricate information on their numbers,true masses,and three-dimensional orbits.Notably,CHES marks a historic milestone as the in-augural international space exploration mission exclusively dedicated to the study of terrestrial planets within the nearby habitable zone.CHES’s payload features a cutting-edge optical telescope with a 1.2 m aperture,a field of view measuring 0.44°×0.44°,and a focal length of 36 m.The telescope utilizes a coa xial three-mirror TMA optical imaging system.Impressively,CHES is designed with a positioning mea-surement accuracy of 1μas,solidifying its status as the most precise space exploration project globally in terms of positioning accuracy.To achieve the detection objectives of CHES,it is essential to refine and further substantiate the scientific goals through comprehensive argumentation.Overcoming three key technological challenges is crucial:advancing optical systems for large field of view,developing high-quality space telescopes with minimal distortion;breaking through measurement technology for stellar separations at the 10–5 pixel level;and achieving high stability in satellite system attitude control and thermal control precision.CHES stands on the threshold of groundbreaking discoveries,with the excit-ing prospect of revealing 50 Earth-like planets.This announces a significant leap forward in China’s space science exploration technology.

关 键 词：高精度天体测量法 系外行星 近邻宜居行星 

分 类 号：P12[天文地球—天体测量]