Examination of Theia 456 finds its nearly 500 stars were born at same time

对Theia 456的检查发现其近500颗恒星同时诞生

An artistic rendering of generic stellar streams in the Milky Way. Credit: NASA/JPL- Caltech/R. Hurt, SSC & Caltech

银河中普通恒星流的艺术渲染。图片来源：NASA / JPL- Caltech / R。南南合作和加州理工学院

The Milky Way houses 8,292 recently discovered stellar streams—all named Theia. But Theia 456 is special.

银河系拥有8,292个最近发现的恒星流-全部都命名为Theia。但是Theia 456是特别的。

A stellar stream is a rare linear pattern—rather than a cluster—of stars. After combining multiple datasets captured by the Gaia space telescope, a team of astrophysicists found that all of Theia 456's 468 stars were born at the same time and are traveling in the same direction across the sky.

恒星流是稀有的线性模式，而不是星团。结合盖亚太空望远镜捕获的多个数据集之后，一组天体物理学家发现，Theia 456的468颗恒星全部同时诞生，并沿相同的方向在天空中飞行。

"Most stellar clusters are formed together," said Jeff Andrews, a Northwestern University astrophysicist and member of the team. "What's exciting about Theia 456 is that it's not a small clump of stars together. It's long and stretched out. There are relatively few streams that are nearby, young and so widely dispersed."

西北大学天体物理学家，研究团队成员杰夫·安德鲁斯（Jeff Andrews）说：“大多数恒星团是一起形成的。” “ Theia 456令人兴奋的是，它不是一团小小的恒星。它又长又延伸。附近的溪流相对较少，年轻且分布广泛。”

Andrews presented this research during a virtual press briefing at the 237th meeting of the American Astronomical Society. "Theia 456: A New Stellar Association in the Galactic Disk" took place today (Jan. 15) as a part of a session on "The Modern Milky Way."

安德鲁斯在美国天文学会第237次会议上的虚拟新闻发布会上介绍了这项研究。作为“现代银河”会议的一部分，今天（1月15日）举行了“ Theia 456：银河盘中的新恒星协会”。

Andrews is a postdoctoral fellow at Northwestern's Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). He conducted this work with astrophysicists Marcel Agüeros and Jason Curtis of Columbia University, Julio Chanamé of Pontifica Universidad Catolica, Simon Schuler of University of Tampa and Kevin Covey and Marina Kounkel of Western Washington University.

安德鲁斯（Andrews）是西北天体物理学跨学科探索与研究中心（CIERA）的博士后。他与哥伦比亚大学的天体物理学家MarcelAgüeros和Jason Curtis，庞蒂菲卡大学的JulioChanamé，坦帕大学的Simon Schuler和西华盛顿大学的Kevin Covey和Marina Kounkel。

While researchers have long known that stars form in groups, most known clusters are spherical in shape. Only recently have astrophysicists started to find new patterns in the sky. They believe long strings of stars were once tight clusters, gradually ripped apart and stretched by tidal forces.

尽管研究人员早就知道恒星是成群形成的，但大多数已知的星团都是球形的。直到最近天体物理学家才开始在天空中寻找新的模式。他们认为，长长的星星串曾经是紧密的星团，逐渐被潮汐撕裂并伸展。

"As we've started to become more advanced in our instrumentation, our technology and our ability to mine data, we've found that stars exist in more structures than clumps," Andrews said. "They often form these streams across the sky. Although we've known about these for decades, we're starting to find hidden ones."

安德鲁斯说：“随着我们在仪器，技术和数据挖掘能力上的日趋先进，我们发现恒星存在的结构多于块状。” “它们经常在天空中形成这些溪流。尽管我们已经知道了数十年，但我们开始发现隐藏的溪流。”

Stretching more than 500 light-years, Theia 456 is one of those hidden streams. Because it dwells within the Milky Way's galactic plane, it's easily lost within the galaxy's backdrop of 400 billion stars. Most stellar streams are found elsewhere in the universe—by telescopes pointed away from the Milky Way.

长达500多年的光年，Theia 456是其中隐藏的溪流之一。由于它驻留在银河系的银河系平面内，因此很容易在银河系拥有4000亿颗恒星的背景下消失。大多数恒星流是在远离银河系的望远镜中发现的，在宇宙的其他地方。

"We tend to focus our telescopes in other directions because it's easier to find things," Andrews said. "Now we're starting to find these streams in the galaxy itself. It's like finding a needle in a haystack. Or, in this case, finding a ripple in an ocean."

安德鲁斯说：“我们倾向于将望远镜聚焦在其他方向，因为它更容易找到东西。” “现在我们开始在银河系本身中发现这些水流。这就像在大海捞针中找到一根针。或者，在这种情况下，就是在海洋中找到涟漪。”

Identifying and examining these structures is a data science challenge. Artificial intelligence algorithms combed huge datasets of stellar data in order to find these structures. Then Andrews developed algorithms to cross-reference those data with pre-existing catalogs of documented stars' iron abundances.

识别和检查这些结构是数据科学的挑战。人工智能算法梳理了巨大的恒星数据集，以找到这些结构。然后，安德鲁斯（Andrews）开发了将这些数据与已记录的恒星铁丰度目录进行交叉引用的算法。

Andrews and his team found that the 468 stars within Theia 456 had similar iron abundances, which means that—100 million years ago—the stars likely formed together. Adding further evidence to this finding, the researchers examined a light curves dataset, which captures how stars' brightness changes over time.

安德鲁斯和他的团队发现，Theia 456内的468颗恒星具有相似的铁丰度，这意味着-一亿年前-这些恒星很可能一起形成。为这一发现增加了进一步的证据，研究人员检查了一个光曲线数据集，该数据集捕获了星星亮度随时间的变化。

"This can be used to measure how fast the stars are spinning," Agüeros said. "Stars with the same age should show a distinct pattern in their spin rates."

阿格罗斯说：“这可以用来衡量恒星旋转的速度。” “同龄的恒星应该显示出不同的自旋速率。”

With the help of data from NASA's Transiting Exoplanet Survey Satellite and from the Zwicky Transient Facility—both of which produced light curves for stars in Theia 456 —Andrews and his colleagues were able to determine that the stars in the stream do share a common age.

借助美国国家航空航天局（NASA）的过渡系外行星测量卫星和兹维基瞬变设施的数据，两者均产生了Theia 456中恒星的光曲线）安德鲁斯和他的同事们能够确定恒星流中的恒星确实有一个共同的年龄。

The team also found that the stars are moving together in the same direction.

研究小组还发现，恒星朝着同一方向移动。

"If you know how the stars are moving, then you can backtrack to find where the stars came from," Andrews said. "As we rolled the clock backwards, the stars became closer and closer together. So, we think all these stars were born together and have a common origin."

安德鲁斯说：“如果你知道恒星是如何运动的，那么就可以回溯找到恒星的来源。” “当我们倒转时钟时，星星变得越来越近。因此，我们认为所有这些恒星都是一起诞生的，并且有共同的起源。”

Andrews said combining datasets and data mining is essential to understanding the universe around us.

安德鲁斯说，将数据集和数据挖掘结合起来对于理解我们周围的宇宙至关重要。

"You can only get so far with one dataset," he said. "When you combine datasets, you get a much richer sense of what's out there in the sky."

他说：“到目前为止，只有一个数据集才能达到目标。” “当组合数据集时，您将对天空中的内容有更丰富的了解。”

点击：查看更多天文学文章
             查看更多双语译文文章
             使用双语译文文档翻译功能

免责声明：福昕翻译只充当翻译功能，此文内容及相关信息仅为传递更多信息之目的，仅代表作者个人观点，与本网站无关，版权归原始网站所有。仅供读者参考，并请自行核实相关内容。若需要浏览原文、下载参考文献等，请自行搜索文中提到的原文网站进行阅读。

 来源于：phys