A Survey of Nearby Very Low Mass Star-Brown Dwarf Spectral Binaries

最冷的恒星和褐矮星的质量不到太阳的10%，构成了银河系中的大多数人口。目前还不清楚这些物体是如何形成的。对实际上由两颗或更多恒星组成的系统中的低质量恒星的比例进行准确测量，可能会限制或排除目前提出的几种理论。提案团队已经开发出一种方法来识别短周期、低质量的多个系统。他们将确定低质量的倍频，对于一些双星系统，他们将测量它们的轨道属性和质量。该计划将特别吸引在科学领域历来代表性不足的学生。分析工具的构建方式将促进高中和本科生参与恒星研究，重点是让来自历史上代表性较低的群体的学生参与科学研究。该计划的主要目标是通过确定体积有限并经偏差校正的“光谱混合”双星的多重性分数来测量极低质量(M0.1毫升)的二进制分数，该系统由其组合光谱学识别。它涉及四项主要研究：(1)在距离太阳25pc的范围内对M7-L5矮星进行近红外光谱测量；(2)分析这些光谱以确定和表征混合光对；(3)进行数值模拟以确定选择函数及其对人口年龄和质量分布的依赖；以及(4)多分量径向和天体测量监测观测，以测量轨道、单个分量质量和自旋轨道排列。在该方案中收集的数据和开发的分析工具将通过Spex棱镜图书馆和虚拟天文台框架公开提供，供更大的社区进行科学调查。

The coolest stars and brown dwarfs, with mass less than 10% that of the Sun, compose the majority population in the Milky Way Galaxy. It is not yet clear how these objects were formed. An accurate measurement of the fraction of low-mass stars that are actually systems of two or more stars can constrain or rule out several currently proposed theories. The proposal team has developed a method to identify short-period, low-mass multiple systems. They will determine the low-mass multiple frequency, and for some binary systems they will measure their orbital properties and masses. The program will specifically engage students historically underrepresented in science fields. Analysis tools will be constructed in a manner that facilitates participation by high school and undergraduate research students in stellar research, with a focus on engaging students from historically underrepresented groups in science.The program's primary goal is to measure the very low mass (M 0.1 Msun) binary fraction by determining a volume-limited and bias-corrected multiplicity fraction of "spectral blend" binaries, systems identified by their combined-light spectroscopy. It involves four primary investigations: (1) a near-infrared spectral survey of M7-L5 dwarfs within 25 pc of the Sun, (2) analysis of these spectra to identify and characterize blended light pairs; (3) numerical simulations to determine the selection function and its dependence on population age and mass distributions; and (4) multi-component radial and astrometric monitoring observations, with full orbital coverage of five previously identified binaries, to measure orbits, individual component masses and spin-orbit alignment. The data collected and analysis tools developed in this program willm be made publicly available through the SpeX Prism Library and Virtual Observatory frameworks for scientific investigations by the larger community.