Astrophysics of Single and Binary Star Formation

对年轻恒星和棕矮星质量的动态测定将通过使用各种工具和技术的广泛观测计划来持续进行。这项工作的动机是恒星下质量的理论质量存在很大的不确定性，缺乏经验校准(温度、光度等)。对于极低质量/年轻恒星，以及不确定的星团中质量比的分布。目标是获得质量为太阳质量1到0.5的恒星的10%以内的动力学质量，以及质量更小的恒星的20%以内的动力学质量。将开展四个具体项目：1)将利用Keck和Gemini天文台激光导星自适应光学系统和哈勃空间望远镜精细制导传感器观测改善年轻可视双星的轨道，包括低质量主序恒星。2)将使用红外望远镜设备和低温回声光谱仪观测光谱双星来探索土卫二中的质量比分布。3)通过观测13CO谱线周围星盘的自转，可以改善两颗前主序恒星的质量，在13CO谱线上，周围的云层亮度应该较低(在以前的12CO测量中，云的扩展发射是一个不确定的来源)。4)棕矮星的动力学质量将通过对棕矮星双星的观测来确定，这将被用来检验理论上的质量-光度关系。这项工作将直接支持研究生在当代仪器和合作研究方面的培训。国家科学基金会资助的石溪大学本科生研究体验项目和石溪大学本科生也将通过独立研究项目参与。这项工作的结果将通过正在进行的每月“天文开放之夜”计划和与当地业余天文团体的讲座向公众传播。

The dynamical determination of the masses of young stars and brown dwarfs will becontinued through an extensive observational program using a variety of tools andtechniques. The work is motivated by substantial uncertainties in theoretical massrelations for substellar masses, the lack of empirical calibrations (temperature,luminosity, etc.) for very low mass/young stars, and uncertainties the distribution of massratios in clusters. The goal is to obtain dynamical masses to within 10% for stars of mass1 to 0.5 that of the Sun, and to within 20% for those of even less mass. Four specificprojects will be undertaken: 1) The orbits of young visual binaries, including low masspre-main sequence stars, will be improved using Keck and Gemini Observatory laserguidestar Adaptive Optics systems and Hubble Space telescope Fine Guidance Sensorobservations. 2) The mass ratio distribution in the Hyades will be explored using theInfrared Telescope Facility and the Cryogenic Echelle Spectrograph to observespectroscopic binaries. 3) Masses of two pre-main sequence stars will be improved byobserving the rotation of circumstellar disks in the 13CO line where the ambient cloudbrightness should be lower (extended emission from the cloud was a source ofuncertainty in previous 12CO measurements). 4) The dynamical masses of brown dwarfswill be determined from observations of brown dwarf binaries, which will be used to testtheoretical mass-luminosity relations.This work will directly support the training of graduate students in contemporaryinstrumentation and collaborative investigations. Both students in the NSF supportedResearch Experiences for Undergraduates program at Stony Brook and Stony Brookundergraduates will also participate through independent research projects. Results of thework will be disseminated to the public through an ongoing monthly "Open Nights inAstronomy" program and talks to local amateur astronomy groups.