The Formation, Evolution, and Fate of Multiple Star Systems

多恒星系统的形成、演化和命运

• 批准号: 1814762
• 负责人: Nathan Kaib
• 金额: $ 28.8万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1814762&HistoricalAwards=false
• 关键词: Formation; Evolution; Fate; Multiple; Star

Stars are born within clouds of dense gas that collapse under their own gravity. Sometimes solitary stars form, like our own Sun. But, stars also commonly form in binary or multiple star systems that are bound by gravity. It remains unknown how most of these binary stars form. One way that they may form is within the disk of gas and dust that forms around the newborn star. They may also first form separately and later become bound due to their own mutual gravity. The number offorming binary systems, their separations, and the environment that the binary stars formed within must be examined to understand why they are so common.The investigators seek to understand formation of binary stars, by finding and examining previously unknown newborn binary stars. These newborn stars will be observed with the NSF's Very Large Array (VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescopes. These high-resolution observations will discover binary stars forming with separations smaller than the size of our own Solar System. They will show where binary stars form, how they most likely formed, and if they will remain in a binary system throughout their lives. This project will help reveal how often Solar Systems like our own form around a single star. As part of this project, radio astronomy will be integrated into undergraduate and graduate education at the University of Oklahoma. Lab activities using the local 3-meter radio telescope will be designed to fulfill educational goals at multiple levels. Collaboration with local high schools will also enable them to conduct radio astronomy observations from their classroom.The investigators will conduct a systematic search for multiple stars. The investigators will analyze surveys of the Orion and Perseus star forming regions, sampling over 400 proto-stars in total, achieving better than 30 Astronomical Unit resolution. The companion separation distributions between Orion and Perseus will be compared between themselves and with the distributions measured for field stars using statistical tests. For a subset of the systems, molecular line imaging from ALMA will be used to verify that the disks are Keplerian and to measure the masses of the proto-stars and estimate their mass ratios. Finally, even if systems lack a companion, but have a clear disk, their likelihood of later fragmentation will be assessed. In addition to this census, their formation conditions will be characterized and the potential for companion formation will be estimated. The investigators will create a clearer picture of multiplicity at the time of early star formation and how the distribution of multiple stars must change as the stellar systems mature to the main sequence.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.

恒星诞生于稠密的气体云中，这些气体在自身引力的作用下坍缩。有时会形成孤独的恒星，就像我们的太阳。但是，恒星也通常形成在双星或多星星系统，由重力约束。目前还不清楚这些双星是如何形成的。 它们可能形成的一种方式是在新生星星周围形成的气体和尘埃盘内。它们也可能首先单独形成，然后由于它们自己的相互引力而结合。双星系统的形成数量、它们的间隔以及双星形成的环境都必须被检查，以了解它们为什么如此普遍。研究人员试图通过发现和检查以前未知的新生双星来了解双星的形成。这些新生恒星将由美国国家科学基金会的甚大阵列（VLA）和阿塔卡马大型毫米/亚毫米阵列（阿尔马）射电望远镜观测。这些高分辨率的观测将发现双星形成的距离小于我们太阳系的大小。 它们将展示双星在哪里形成，它们最有可能如何形成，以及它们是否会在整个生命中保持在双星系统中。这个项目将有助于揭示太阳系像我们自己一样围绕一颗星星形成的频率。作为该项目的一部分，射电天文学将被纳入俄克拉荷马州大学的本科和研究生教育。使用当地3米射电望远镜的实验室活动将被设计为实现多层次的教育目标。与当地高中的合作也将使他们能够在课堂上进行射电天文学观测。调查人员将对多颗恒星进行系统的搜索。 研究人员将分析猎户座和英仙座星星形成区域的调查，总共对400多颗原恒星进行采样，达到超过30个天文单位的分辨率。 猎户座和英仙座之间的伴星分离分布将在它们之间进行比较，并与使用统计检验测量的场星分布进行比较。对于这些系统的一个子集，将使用阿尔马的分子线成像来验证盘是开普勒的，并测量原恒星的质量和估计它们的质量比。最后，即使系统没有伴星，但有一个清晰的磁盘，它们以后碎裂的可能性也将得到评估。除了这次普查，他们的形成条件的特点和潜在的同伴形成将估计。 研究人员将创建一个更清晰的图片的多样性在早期星星形成的时间，以及如何分布的多颗恒星必须改变恒星系统成熟的主序星。这个奖项反映了美国国家科学基金会的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

项目成果

A 16 au Binary in the Class 0 Protostar L1157 MMS

• DOI: 10.3847/1538-4357/ac5594
• 发表时间: 2022-02
• 期刊: The Astrophysical Journal
• 作者: J. Tobin;E. Cox;L. Looney

Constraining the Chemical Signatures and the Outburst Mechanism of the Class 0 Protostar HOPS 383

• DOI: 10.3847/1538-4357/abbdf4
• 发表时间: 2020-10
• 期刊: The Astrophysical Journal
• 作者: Rajeeb Sharma;J. Tobin;P. Sheehan;S. Megeath;W. Fischer;J. Jørgensen;E. Safron;Z. Nagy

Dynamical fates of S-type planetary systems in embedded cluster environments

嵌入式星团环境中 S 型行星系统的动力学命运

• DOI: 10.1093/mnras/stac1973
• 发表时间: 2022
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Ellithorpe, Elizabeth A.;Kaib, Nathan A.
• 通讯作者: Kaib, Nathan A.

Kinematic Analysis of a Protostellar Multiple System: Measuring the Protostar Masses and Assessing Gravitational Instability in the Disks of L1448 IRS3B and L1448 IRS3A

原恒星多重系统的运动学分析：测量原恒星质量并评估 L1448 IRS3B 和 L1448 IRS3A 盘中的引力不稳定性

• DOI: 10.3847/2041-8213/abcc02
• 发表时间: 2021
• 期刊: The Astrophysical Journal Letters
• 作者: Reynolds, Nickalas K.;Tobin, John J.;Sheehan, Patrick;Sadavoy, Sarah I.;Kratter, Kaitlin M.;Li, Zhi-Yun;Chandler, Claire J.;Segura-Cox, Dominique;Looney, Leslie W.;Dunham, Michael M.
• 通讯作者: Dunham, Michael M.

Dissecting the Different Components of the Modest Accretion Bursts of the Very Young Protostar HOPS 373

• DOI: 10.3847/1538-4357/ac5632
• 发表时间: 2022-02
• 期刊: The Astrophysical Journal
• 作者: Sung-yong Yoon;G. Herczeg;Jeong-Eun Lee;Ho-Gyu Lee;D. Johnstone;W. Varricatt;J. Tobin;C. C. Peña-C.-C.