Title: Detection of solar-like oscillations from Kepler photometry of the open cluster NGC 6819 Show Chinese title

Title: 从开普勒对疏散星团 NGC 6819 的光度观测中检测到类太阳振荡

Abstract: Asteroseismology of stars in clusters has been a long-sought goal because the assumption of a common age, distance and initial chemical composition allows strong tests of the theory of stellar evolution. We report results from the first 34 days of science data from the Kepler Mission for the open cluster NGC 6819 -- one of four clusters in the field of view. We obtain the first clear detections of solar-like oscillations in the cluster red giants and are able to measure the large frequency separation and the frequency of maximum oscillation power. We find that the asteroseismic parameters allow us to test cluster-membership of the stars, and even with the limited seismic data in hand, we can already identify four possible non-members despite their having a better than 80% membership probability from radial velocity measurements. We are also able to determine the oscillation amplitudes for stars that span about two orders of magnitude in luminosity and find good agreement with the prediction that oscillation amplitudes scale as the luminosity to the power of 0.7. These early results demonstrate the unique potential of asteroseismology of the stellar clusters observed by Kepler. Show Chinese abstract

Abstract: 恒星集群中的星震学一直是长期追求的目标，因为假设共同的年龄、距离和初始化学成分使得对恒星演化的理论进行强有力的测试成为可能。 我们报告了开普勒任务科学数据前34天的结果，针对开放集群NGC 6819——视场中的四个集群之一。 我们首次在集群红巨星中检测到类似太阳的振荡，并能够测量大的频率间隔和最大振荡功率的频率。 我们发现，星震参数使我们能够测试恒星的集群成员身份，即使目前的地震数据有限，我们已经可以识别出四个可能的非成员，尽管它们的径向速度测量显示其成员概率超过80%。 我们还能够确定跨越约两个数量级光度的恒星的振荡振幅，并发现与振荡振幅按光度的0.7次方变化的预测有良好一致性。 这些早期结果展示了开普勒观测的恒星集群星震学的独特潜力。