Discovery of New Small, Cool Planets Orbiting M-Dwarf Stars

最冷、最古老的恒星被称为M矮星。因为它们的温度更低，所以它们周围可能有许多地球大小的行星，这些行星有生命存在的条件。研究人员将结合开普勒宇宙飞船“K2”任务和地球上的望远镜的观测结果，制作已知最大的M矮星周围行星样本。他们将测量出现在不同类型恒星上的行星的数量和特征，并找到并确认我们所理解的可能存在生命的行星。这些行星随后成为未来太空望远镜的目标，如詹姆斯·韦伯太空望远镜，以进一步深入研究。这项研究扩大了我们对可能存在生命的系外行星的科学知识，符合国家利益。研究人员将与图森的弗兰德劳科学中心和天文馆合作，让社区参与到太阳系外行星的发现和研究中来，包括支持当地缺乏服务的学生群体进行实地考察。M型矮星为寻找地球大小的、可能适合居住的岩石行星，以及研究它们出现的频率和特征提供了最好的前景。然而，这些目标大部分仍未实现，因为过去的调查在很大程度上忽略了M矮星，而倾向于类太阳恒星。这项研究将支持先前通过扩展的开普勒航天器K2任务和关键的地面望远镜支持设施进行的非常成功的调查，以产生已知最大的围绕M恒星的行星样本。研究人员将测量行星出现频率作为恒星和行星特性的函数；填补低质量系统地层模型的关键空白；寻找可能适合居住的行星；并找到有吸引力的目标，用未来的詹姆斯·韦伯太空望远镜进行大气表征。在K2数据发布后，研究人员将提取光度测定数据，识别和验证候选行星。然后，他们获得后续的成像和光谱学来识别假阳性，对恒星进行分类，并验证行星。K2光曲线、侦察光谱和径向速度数据的组合确定了精确的恒星和行星参数。最后，对所有数据进行全球综合，测量M矮星周围行星的调查完整性和全球发生率，包括可居住的岩石行星的频率。研究人员将与图森的弗兰德劳科学中心和天文馆合作，参与社区对太阳系外行星的发现和研究，包括支持当地缺乏服务的学生群体进行实地考察。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The coolest and oldest stars are known as the M dwarf stars. Because they are cooler, they could have many Earth-sized planets around them that have the means of hosting life. The investigators will combine observations from the Kepler spacecraft mission "K2", and from telescopes on the Earth, to make the largest-known sample of planets around M dwarf stars. They will measure the number and characteristics of planets that occur for different types of stars, and find and confirm planets that could host life as we understand it. These planets then become targets for future space telescopes such as the James Webb Space Telescope to study further in depth. This research serves the national interest by expanding our scientific knowledge about extrasolar planets that could host life. The investigators will work with Tucson's Flandrau Science Center and Planetarium to engage the community on the discovery and study of extrasolar planets, including supporting field trips by local, underserved student populations.M dwarf stars offer the best prospects for finding rocky, Earth-sized, potentially habitable planets, and for studying their frequency of occurrence and their characteristics. These goals, however, remain mostly unrealized because past surveys have largely overlooked M dwarf stars in favor of solar-like stars. This research will support previous highly-successful surveys with the extended Kepler spacecraft mission K2, and key ground-based telescopic support facilities, to produce the largest known sample of planets around M stars. The investigators will measure planet occurrence frequency as a function of stellar and planetary properties; fill key gaps in formation models of low-mass systems; find potentially habitable planets; and find attractive targets for atmospheric characterization with the future James Webb Space Telescope. After K2 data are released, the investigators will extract photometry, identify and validate planet candidates. They then acquire follow-up imaging and spectroscopy to identify false positives, classify stars, and validate planets. The combination of K2 light curves, reconnaissance spectra, and radial velocity data determine precise stellar and planetary parameters. Finally, a global synthesis of all data measures the survey completeness and global occurrence rate of planets around M dwarf stars, including the frequency of habitable, rocky planets. The investigators will partner with Tucson's Flandrau Science Center and Planetarium to engage the community on the discovery and study of extrasolar planets, including supporting field trips by local, underserved student populations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.