Kepler 空间望远镜在 2009 至 2018 的十年任务期间观测了约 80 万颗恒 星，为天体物理许多领域提供了前所未有的超高精度时序测光数据，显著推 动了系外行星、星震学、双星、恒星耀发等领域的进展。然而，Kepler 数据 缺少可靠的恒星参数。虽然这些参数可以用通用地基望远镜进行光谱观测获 得，但想要覆盖 Kepler 及 K2 天区数十万颗目标极为困难，阻碍了其发挥应 有的科学潜力。多年来 LAMOST 望远镜的光谱获取效率世界第一，是进行 Kepler 及 K2 天区大样本恒星光谱覆盖观测的最佳设备，从 2012 年开始的 LAMOST-Kepler（L-K）项目以及跟进的 LAMOST-K2（L-K2）项目也证实了 这一点。截至 2021 年 6 月，LAMOST 对 Kepler 天区的覆盖率达到了 44%，对 K2 天区可观测目标的覆盖达到了 41%。然而，当前 LAMOST 所在的兴隆观 测基地由于气候因素以及城市光污染的日益严重，已无法充分发挥 LAMOST 望远镜的观测能力。 对青海冷湖长达三年的监测表明这里是世界级天文台址，LAMOST 二期 工程提出要将 LAMOST 望远镜搬迁于此。届时，极限星等、光纤数、晴夜数 三个主要方面的提升将使 LAMOST 充分发挥其观测潜力，对我国在银河系 与恒星光谱巡天领域保持世界领先地位有重要意义。我们对 LAMOST 搬迁 后 L-K 及 L-K2 项目的提升进行了预研究，结果显示 LAMOST 在冷湖台址对 Kepler 天区的覆盖将能在两个观测季达到 80%，对 K2 天区也将在四年后达 到 70%。

Since 2009, the Kepler Space Telescope has observed about 800,000 stars, providing an unprecedented amount of ultra-high-precision photometric data for astrophysics, and greatly promoting advances in exoplanets, asteroseismology, binary stars, galaxies and other fields. However, Kepler data lacks high-precision stellar parameters obtained from spectra, and although it can be observed with ground-based spectral telescopes, it is extremely difficult to cover the targets of Kepler and K2 regions, which hinders its scientific potential. At present, LAMOST has the highest efficiency in spectral acquisition all over the world, and it is the best equipment for spectral coverage observations in the Kepler and K2 regions, which is confirmed by the LAMOST-Kepler project from 2012 and the follow-up LAMOST-K2 project. Until June 2021, LAMOST’s coverage of the Kepler sky area has reached 44%, and the coverage of observable targets in the K2 sky area has reached 41%. However, due to the Monsoon and the increasingly serious light pollution in the city, the Xinglong Observation site, where LAMOST is currently located, has been unable to match the observation capabilities of the telescope. The exploration of Lenghu in Qinghai province has proven that it is a world-class astronomical observatory site, and LAMOST Phase II project proposed to relocate the LAMOST telescope here. At that time, the improvement in limiting magnitude, fiber number, observable night numbers will allow LAMOST fully utilize its observation potential, which is of great significance for China to maintain the world’s leading position in the Milky Way and stellar spectrum survey field. Here, we conducted a pre-study of the upgrading of L-K and L-K2 projects after LAMOST moving to Lenghu, and the results show that the coverage of Kepler targets will reach 80% in two observation seasons, and of K2 targes will reach 70% after four years.