Astronomers have revolutionized our understanding of a collection of stars in the northern sky called the Pleiades. They used data from NASA’s TESS (Transiting Exoplanet Survey Satellite) and other observatories as NASA explores the secrets of the universe for the benefit of all, from the Moon to Mars and beyond.
天文学家彻底改变了我们对北方天空中称为昴宿星团的恒星集合的理解。他们使用来自 NASA 的 TESS（凌日系外行星勘测卫星）和其他天文台的数据，NASA 探索宇宙的秘密，造福从月球到火星及其他地方的所有人。
By examining the rotation, chemistry, and orbit around the Milky Way of members of several different nearby stellar groups, the scientists identified a continuum of more than 3,000 stars arcing across 1,900 light-years. This Greater Pleiades Complex triples the number of stars associated with the Pleiades and opens new approaches for discovering similar dispersed star clusters in the future.
通过检查附近几个不同恒星群成员的旋转、化学和绕银河系的轨道，科学家们确定了一个由 3,000 多颗恒星组成的连续体，弧线横跨 1,900 光年。这个更大的昴宿星团使与昴宿星团相关的恒星数量增加了三倍，并为未来发现类似的分散星团开辟了新的方法。
“The Pleiades are very well studied — we often use them as a benchmark in astronomical observations,” said Andrew Boyle, a graduate student at the University of North Carolina at Chapel Hill. “When I started this research, I didn’t expect the cluster to balloon to the size that it did. It really touches on a human note. In the Northern Hemisphere, we’ve been looking up at the Pleiades and telling stories about them for thousands of years, but there’s so much more to them than we knew.”
“昴宿星团得到了很好的研究——我们经常用它们作为天文观测的基准，”北卡罗来纳大学教堂山分校的研究生安德鲁·博伊尔说。 “当我开始这项研究时，我并没有想到这个星团会膨胀到现在的大小。它确实触及了人类的本质。在北半球，我们几千年来一直仰望昴宿星团并讲述它们的故事，但它们的内涵比我们所知的要多得多。”
A paper about the result, led by Boyle, published Wednesday, Nov. 12, in the Astrophysical Journal.
由博伊尔领导的关于这一结果的论文于 11 月 12 日星期三发表在《天体物理学杂志》上。
The Pleiades is a bright cluster of stars, also known as Messier 45 . This loose grouping of about 1,000 members was born roughly 100 million years ago from the same molecular cloud, a cold dense patch of gas and dust.
昴宿星团是一个明亮的星团，也称为梅西耶 45。这个由大约 1,000 个成员组成的松散群体诞生于大约 1 亿年前的同一个分子云（一片寒冷而密集的气体和尘埃）中。
About six of the stars in the cluster are visible to the unaided eye during evenings from October to April in the northern constellation Taurus. This collection has also been known since antiquity as the Seven Sisters, although the seventh star is no longer visible.
从十月到四月的夜晚，在北部金牛座，肉眼可以看到星团中大约六颗恒星。该系列自古以来也被称为七姐妹星，尽管第七颗星已不再可见。
Boyle and his team initially identified over 10,000 stars that could be related to the Pleiades. These stars were orbiting at a similar rate around our Milky Way galaxy according to data from ESA’s (European Space Agency) Gaia satellite.
博伊尔和他的团队最初确定了超过 10,000 颗可能与昴宿星团有关的恒星。根据欧空局（欧洲航天局）盖亚卫星的数据，这些恒星以相似的速度围绕我们的银河系运行。
They narrowed down that collection using stellar rotation data from TESS.
他们利用来自 TESS 的恒星旋转数据缩小了收集范围。
NASA’s TESS mission scans a wide swath of the sky for about a month at a time, looking for variations in the light from stars to spot orbiting planets. This technique also allows TESS to identify and monitor asteroids out to large distances, determining their spin and refining their shape. Such observations improve our understanding of asteroids in our solar system, which can aid in planetary defense.
NASA 的 TESS 任务每次扫描大片天空约一个月，寻找恒星光线的变化，以发现绕轨道运行的行星。这项技术还使 TESS 能够识别和监测远距离的小行星，确定它们的自转并改善它们的形状。这些观测提高了我们对太阳系小行星的了解，这有助于行星防御。
Scientists can also use TESS data to determine how fast the stars are rotating by looking at regular fluctuations in their light caused when dark surface features called star spots come in and out of view. Because stellar rotation slows as stars age, the researchers were able to pick out the stars that were about the same age as the Pleiades.
科学家还可以利用 TESS 数据，通过观察被称为星斑的黑暗表面特征进入和消失时引起的光线规律波动来确定恒星旋转的速度。由于恒星自转随着恒星年龄的增长而减慢，研究人员能够挑选出与昴宿星团年龄大致相同的恒星。
The team also looked at the chemical abundances in potential members using data from ground-based missions like the Sloan Digital Sky Survey , which is led by a consortium of institutions.
该团队还使用来自地面任务（例如由一个机构联盟领导的斯隆数字巡天任务）的数据来研究潜在成员的化学丰度。
“The core of the Pleiades is chemically distinct from the average star in a few elements like magnesium and silicon,” said Luke Bouma, a co-author and fellow at the Carnegie Science Observatories in Pasadena, California. “The other stars that we propose are part of the Greater Pleiades are chemically distinct in the same way. The combination of these three major lines of evidence — Milky Way orbits, ages, and chemistry — tells me that we’re on the right path when making these connections.”
加州帕萨迪纳卡内基科学天文台的合著者兼研究员卢克·鲍马（Luke Bouma）表示：“昴宿星团核心的化学成分与普通恒星的镁和硅等元素不同。” “我们提出的属于大昴宿星团一部分的其他恒星在化学上也同样不同。这三个主要证据——银河系轨道、年龄和化学——的结合告诉我，我们在建立这些联系时走在正确的道路上。”
The team members think that all the stars in the Greater Pleiades Complex formed in a tighter collection, like the stars in the young Orion cluster, about 100 million years ago. Over time, the cluster dispersed due to the explosive forces of internal supernovae and from the tidal forces of our galaxy’s gravity.
研究小组成员认为，大昴宿星团中的所有恒星都形成了一个更紧密的集合，就像大约一亿年前年轻的猎户座星团中的恒星一样。随着时间的推移，由于内部超新星的爆炸力和银河系引力的潮汐力，该星团分散了。
The result is a stream of stars arcing across the sky from horizon to horizon.
结果是一道星星流在天空中从地平线到地平线划过。
Boyle and Bouma are now working on what they call the TESS All-Sky Rotation Survey. This database will allow researchers to access the rotation information for over 8 million stars to discover even more hidden stellar connections like the Greater Pleiades Complex.
博伊尔和鲍玛目前正在开展他们所谓的 TESS 全天旋转巡天项目。该数据库将使研究人员能够访问超过 800 万颗恒星的旋转信息，以发现更多隐藏的恒星连接，例如大昴宿星团。
“Thanks to TESS, this team was able to shed new light on a fixture of astronomy,” said Allison Youngblood, the TESS project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “From distant stars and planets to asteroids in our solar system and machine learning models here on Earth, TESS continues to push the boundaries of what we can accomplish with large datasets that capture just a part of the complexity of our universe.”
“感谢 TESS，这个团队能够为天文学的固定装置提供新的线索，”马里兰州格林贝尔特 NASA 戈达德太空飞行中心的 TESS 项目科学家 Allison Youngblood 说。 “从遥远的恒星和行星到太阳系中的小行星，再到地球上的机器学习模型，TESS 不断突破我们利用大型数据集所能实现的极限，这些数据集只捕获了宇宙复杂性的一部分。”
By Jeanette Kazmierczak NASA’s Goddard Space Flight Center , Greenbelt, Md.
作者：Jeanette Kazmierczak 美国宇航局戈达德太空飞行中心，马里兰州格林贝尔特
Media Contact: Claire Andreoli 301-286-1940 NASA’s Goddard Space Flight Center, Greenbelt, Md.
媒体联系人：克莱尔·安德烈奥利 (Claire Andreoli) 301-286-1940 美国宇航局戈达德太空飞行中心，马里兰州格林贝尔特