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

最冷的恒星和褐矮星，质量不到太阳的10%，构成了银河系的大多数人口。目前还不清楚这些天体是如何形成的。精确测量实际上由两颗或两颗以上恒星组成的低质量恒星的比例，可以限制或排除目前提出的一些理论。提案团队开发了一种方法来识别短周期、低质量的多系统。他们将确定低质量的多重频率，对于一些双星系统，他们将测量它们的轨道性质和质量。该项目将特别吸引在科学领域历史上代表性不足的学生。分析工具将以一种促进高中和本科生参与恒星研究的方式构建，重点是吸引来自历史上代表性不足的科学群体的学生。该计划的主要目标是通过确定“光谱混合”双星的体积限制和偏差校正的多重分数来测量非常低质量（m0.1 Msun）的双星分数，系统由它们的组合光谱学识别。它包括四个主要研究：(1)对距离太阳25pc内的M7-L5矮星进行近红外光谱调查；(2)对这些光谱进行分析，以识别和表征混合光对；(3)通过数值模拟确定选择函数及其对人口年龄和质量分布的依赖关系；(4)多分量径向和天体测量监测观测，对先前确定的五个双星进行全轨道覆盖，测量轨道、单个分量质量和自旋轨道对准。在这个项目中收集的数据和开发的分析工具将通过SpeX棱镜库和虚拟天文台框架公开，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.