Theoretical Models of Binary Star and Brown Dwarf Formation

博斯，阿兰AST 0305913 PI将提高对双星、棕矮星和亚棕矮星形成的理解。发现前主序星的伴星，其频率至少等于主序星的频率，要求双星星星的形成发生在恒星演化的前主序星阶段之前，即，在原恒星坍缩阶段。虽然太阳质量恒星的褐矮星伴星似乎很罕见，但已知的自由漂浮的褐矮星数量很大，而且还在增加。褐矮星双星很常见，可能已经发现了几颗亚褐矮星，其质量通常与气体巨行星有关。双星被假设是在原恒星坍缩过程中通过碎裂形成的，这一过程可以导致质量越来越小的原恒星的形成。该项目将通过详细的分子云核坍缩模型，进一步发展原恒星碎裂理论。这些模型将有助于人们更好地理解双星和多星星的形成，以及新形成的原恒星碎片的最小质量。这项工作的更广泛影响集中在PI努力向公众传达科学发现的兴奋，通过与记者的频繁互动，举办公开讲座，帮助博物馆举办展览，并为流行杂志撰写文章。PI还指导本科生作为NSF REU计划的一部分。

Boss, AlanAST 0305913The PI will improve the understanding of the formation of binary, brown dwarf, and sub-brown dwarf stars. The discovery of companions to pre-main sequence stars with a frequency at least equal to that of main sequence stars requires that binary star formation occur prior to the pre-main-sequence phase of stellar evolution, i.e., during the protostellar collapse phase. While brown dwarf companions to solar-mass stars appear to be rare, the number of known free-floating brown dwarf stars is large and growing. Brown dwarf binaries are common, and several sub-brown dwarfs may have been discovered with masses in the range generally associated with gas giant planets. Binary stars are hypothesized to form by fragmentation during protostellar collapse, a process that can lead to the formation of increasingly smaller mass protostars. This project will further develop the theory of protostellar fragmentation, through detailed models of the collapse of molecular cloud cores. The models will result in an improved understanding of binary and multiple star formation, as well as of the minimum mass of a newly-formed protostellar fragment.The broader impact of this work centers on the PI's efforts to communicate the excitement of scientific discoveries to the public, through frequent interactions with journalists, giving public lectures, helping museums with exhibits, and writing articles for popular magazines. The PI also mentors undergraduate students as a part of an NSF REU program.