Department of Physics and Astronomy, George Mason University, Fairfax, VA, USA.
Center for Space Sciences and Technology, University of Maryland Baltimore County (UMBC), Baltimore, MD, USA.
Nature. 2020 Jun;582(7813):497-500. doi: 10.1038/s41586-020-2400-z. Epub 2020 Jun 24.
AU Microscopii (AU Mic) is the second closest pre-main-sequence star, at a distance of 9.79 parsecs and with an age of 22 million years. AU Mic possesses a relatively rare and spatially resolved edge-on debris disk extending from about 35 to 210 astronomical units from the star, and with clumps exhibiting non-Keplerian motion. Detection of newly formed planets around such a star is challenged by the presence of spots, plage, flares and other manifestations of magnetic 'activity' on the star. Here we report observations of a planet transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of 8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4 Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3σ confidence. Our observations of a planet co-existing with a debris disk offer the opportunity to test the predictions of current models of planet formation and evolution.
半人马座 AU（AU Mic）是第二近的主序前恒星，距离为 9.79 秒差距，年龄为 2200 万年。AU Mic 拥有一个相对罕见的、空间分辨率较高的侧向碎片盘，从大约 35 到 210 个天文单位的距离延伸到恒星，并且具有非开普勒运动的团块。在这样的恒星周围检测新形成的行星受到恒星上斑点、光斑、耀斑和其他磁“活动”表现的影响。在这里，我们报告了对 AU Mic 凌日行星的观测结果。这颗凌日行星 AU Mic b 的轨道周期为 8.46 天，轨道距离为 0.07 天文单位，半径为 0.4 木星半径，质量小于 0.18 木星质量，置信度为 3σ。我们对一颗与碎片盘共存的行星的观测为当前行星形成和演化模型的预测提供了检验机会。
