Phase II of the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST)-Kepler/K2 survey (LK–MRS), initiated in 2018, aims at collecting medium-resolution spectra (R∼7500; hereafter MRS) for more than 50,000 stars with multiple visits (∼60 epochs) over a period of 5 yr (2018 September to 2023 June). We selected 20 footprints distributed across the Kepler field and six K2 campaigns, with each plate containing a number of stars ranging from ∼2000 to ∼3000. During the first year of observations, the LK–MRS has already visited 13 plates 223 times over 40 individual nights, and collected ∼280,000 and ∼369,000 high-quality spectra in the blue and red wavelength ranges, respectively. The atmospheric parameters and radial velocities for ∼259,000 spectra of 21,053 targets were successfully calculated by the LAMOST stellar parameter pipeline. The internal uncertainties for the effective temperature, surface gravity, metallicity, and radial velocity are found to be 100 K, 0.15 dex, 0.09 dex, and 1.00 km s⁻¹, respectively, when derived from a medium-resolution LAMOST spectrum with a signal-to-noise ratio (S/N) in the g band of 10. All of the uncertainties decrease as S/N increases, but they stabilize for S/N>100. We found 14,997, 20,091, and 1514 stars in common with the targets from the LAMOST low-resolution survey (LRS), Gaia, and the Apache Point Observatory Galactic Evolution Experiment (APOGEE), respectively, corresponding to fractions of ∼70%, ∼95%, and ∼7.2%. In general, the parameters derived from LK–MRS spectra are consistent with those obtained from the LRS and APOGEE spectra, but the scatter increases as the surface gravity decreases when comparing with the measurements from APOGEE. A large discrepancy is found with the Gaia values of the effective temperature. Comparisons of the radial velocities of LK–MRS to Gaia and LK–MRS to APOGEE nearly follow a Gaussian distribution with means of μ∼1.10 and 0.73 km s⁻¹, respectively. We expect that the results from the LK–MRS spectra will shed new light on binary stars, asteroseismology, stellar activity, and other research fields.

大天区多目标光纤光谱望远镜 (LAMOST)-开普勒/K2 巡天 (LK-MRS) 的第二阶段于 2018 年启动，旨在收集中分辨率光谱 ( R～7500；此后的 MRS）对超过 50,000 颗在 5 年（2018 年 9 月至 2023 年 6 月）期间多次访问（约 60 个时期）的恒星进行了研究。我们选择了分布在开普勒场和 6 个 K2 活动中的 20 个足迹，每个板块包含从 ~2000 到 ~3000 不等的恒星数量。在观测的第一年，LK-MRS 已经在 40 个单独的夜晚访问了 13 个板块 223 次，并分别收集了约 280,000 和约 369,000 个蓝色和红色波长范围的高质量光谱。LAMOST 恒星参数管道成功计算了 21,053 个目标的~259,000 个光谱的大气参数和径向速度。发现有效温度、表面重力、金属丰度和径向速度的内部不确定性为 100 K、0.15 dex、0.09 dex 和 1.00 km s^-1，分别，当从具有信噪比 (S/N) 在g 中的中等分辨率 LAMOST 谱中导出时频带为 10。所有不确定性随着 S/N 的增加而降低，但它们在 S/N>100 时稳定。我们分别发现了 14,997、20,091 和 1514 颗与来自 LAMOST 低分辨率巡天 (LRS)、盖亚和阿帕奇点天文台银河演化实验 (APOGEE) 的目标相同的恒星，对应于约 70%、∼ 95% 和 ~7.2%。通常，从 LK-MRS 光谱导出的参数与从 LRS 和 APOGEE 光谱获得的参数一致，但与 APOGEE 的测量值相比，随着表面重力的降低，散射增加。发现与有效温度的盖亚值存在很大差异。LK-MRS的盖亚和LK-MRS到APOGEE的径向速度的比较近遵循高斯分布的手段μ ~1.10和0.73公里S^-1，分别。我们预计 LK-MRS 光谱的结果将为双星、星震学、恒星活动和其他研究领域带来新的启示。