Using new observations from NASA’s Hubble Space Telescope and ground-based observatories, astronomers tracked the influence of a recently discovered companion star, Siwarha, on the gas around Betelgeuse. The research, from scientists at the Center for Astrophysics | Harvard & Smithsonian (CfA), reveals a trail of dense gas swirling through Betelgeuse’s vast, extended atmosphere, shedding light on why the giant star’s brightness and atmosphere have changed in strange and unusual ways.
利用美国宇航局哈勃太空望远镜和地面天文台的新观测结果，天文学家追踪了最近发现的伴星 Siwarha 对参宿四周围气体的影响。天体物理中心科学家的这项研究|哈佛和史密森尼 (CfA) 揭示了参宿四广阔而广阔的大气层中盘旋的浓密气体痕迹，揭示了为什么这颗巨星的亮度和大气层会以奇怪和不寻常的方式发生变化。
The results of the new study were presented Monday at a news conference at the 247th meeting of the American Astronomical Society in Phoenix and are accepted for publication in The Astrophysical Journal .
这项新研究的结果周一在凤凰城举行的美国天文学会第 247 届会议的新闻发布会上公布，并被《天体物理学杂志》接受发表。
The team detected Siwarha’s wake by carefully tracking changes in the star’s light over nearly eight years. These changes show the effects of the previously unconfirmed companion as it plows through the outer atmosphere of Betelgeuse. This discovery resolves one of the biggest mysteries about the giant star, helping scientists to explain how it behaves and evolves while opening new doors to understanding other massive stars nearing the end of their lives.
研究小组通过仔细跟踪近八年来恒星光线的变化来检测到西瓦哈的尾迹。这些变化显示了之前未经证实的伴星在穿过参宿四外层大气时的影响。这一发现解决了关于这颗巨星的最大谜团之一，帮助科学家解释它的行为和演化方式，同时为了解其他接近生命尽头的大质量恒星打开了新的大门。
Located roughly 650 light-years away from Earth in the constellation Orion, Betelgeuse is a red supergiant star so large that more than 400 million Suns could fit inside. Because of its enormous size and proximity, Betelgeuse is one of the few stars whose surface and surrounding atmosphere can be directly observed by astronomers, making it an important and accessible laboratory for studying how giant stars age, lose mass, and eventually explode as supernovae.
参宿四位于猎户座，距离地球约 650 光年，是一颗红超巨星，其体积之大足以容纳 4 亿多个太阳。由于其巨大的尺寸和距离，参宿四是天文学家可以直接观察其表面和周围大气的少数恒星之一，使其成为研究巨星如何老化、失去质量并最终爆炸为超新星的重要且易于使用的实验室。
Using NASA’s Hubble and ground-based telescopes at the Fred Lawrence Whipple Observatory and Roque de Los Muchachos Observatory, the team was able to see a pattern of changes in Betelgeuse, which provided clear evidence of a long-suspected companion star and its impact on the red supergiant’s outer atmosphere. Those include changes in the star’s spectrum, or the specific colors of light given off by different elements, and the speed and direction of gases in the outer atmosphere due to a trail of denser material, or wake. This trail appears just after the companion crosses in front of Betelgeuse every six years, or about 2,100 days, confirming theoretical models.
利用美国宇航局的哈勃望远镜以及弗雷德·劳伦斯·惠普尔天文台和罗克·德洛斯·穆查霍斯天文台的地面望远镜，研究小组能够看到参宿四的变化模式，这为长期怀疑的伴星及其对红超巨星外层大气的影响提供了明确的证据。这些变化包括恒星光谱的变化，或不同元素发出的特定颜色的光，以及由于密集物质或尾流导致的外层大气中气体的速度和方向。这条踪迹出现在伴星每六年（即大约 2,100 天）经过参宿四前方之后，证实了理论模型。
“It’s a bit like a boat moving through water. The companion star creates a ripple effect in Betelgeuse’s atmosphere that we can actually see in the data,” said Andrea Dupree, an astronomer at the CfA, and the lead study author. “For the first time, we’re seeing direct signs of this wake, or trail of gas, confirming that Betelgeuse really does have a hidden companion shaping its appearance and behavior.”
“这有点像一艘在水中移动的船。伴星在参宿四的大气层中产生了连锁反应，我们实际上可以在数据中看到这一点，”CfA 的天文学家、该研究的主要作者安德里亚·杜普雷 (Andrea Dupree) 说。 “我们第一次看到这种尾迹或气体痕迹的直接迹象，证实参宿四确实有一个隐藏的同伴塑造了它的外观和行为。”
For decades, astronomers have tracked changes in Betelgeuse’s brightness and surface features in hopes of figuring out why the star behaves the way it does. Curiosity intensified after the giant star appeared to “sneeze” and became unexpectedly faint in 2020. Two distinct periods of variation in the star were especially puzzling for scientists: a short 400-day cycle, recently attributed to pulsations within the star itself, and the long, 2,100-day secondary period.
几十年来，天文学家一直在追踪参宿四的亮度和表面特征的变化，希望找出这颗恒星行为方式的原因。在这颗巨星似乎“打喷嚏”并在 2020 年出人意料地变得微弱之后，人们的好奇心更加强烈。这颗恒星的两个不同的变化周期对科学家来说尤其令人困惑：一个是 400 天的短周期，最近归因于恒星内部的脉动，另一个是 2100 天的长第二周期。
Until now, scientists have considered everything from large convection cells and clouds of dust to magnetic activity, and the possibility of a hidden companion star. Recent studies concluded that the long secondary period was best explained by the presence of a low-mass companion orbiting deep within Betelgeuse’s atmosphere, and another team of scientists reported a possible detection, but until now, astronomers lacked the evidence to prove what they believed was happening. Now, for the first time, they have firm evidence that a companion is disrupting the atmosphere of this supergiant star.
到目前为止，科学家们已经考虑了从大型对流单元和尘埃云到磁活动以及隐藏伴星的可能性的一切。最近的研究得出的结论是，长第二周期最好的解释是参宿四大气层深处存在一个低质量伴星，另一组科学家报告了可能的探测结果，但到目前为止，天文学家缺乏证据来证明他们认为正在发生的事情。现在，他们第一次有确凿的证据表明，一颗伴星正在扰乱这颗超巨星的大气层。
“The idea that Betelgeuse had an undetected companion has been gaining in popularity for the past several years, but without direct evidence, it was an unproven theory,” said Dupree. “With this new direct evidence, Betelgeuse gives us a front-row seat to watch how a giant star changes over time. Finding the wake from its companion means we can now understand how stars like this evolve, shed material, and eventually explode as supernovae.”
杜普雷说：“参宿四有一个未被发现的同伴的想法在过去几年里越来越流行，但由于没有直接证据，这是一个未经证实的理论。” “有了这个新的直接证据，参宿四为我们提供了一个观察巨星如何随时间变化的前排座位。找到伴星的尾流意味着我们现在可以了解像这样的恒星如何演化、脱落物质并最终爆炸为超新星。”
With Betelgeuse now eclipsing its companion from our point of view, astronomers are planning new observations for its next emergence in 2027. This breakthrough may also help explain similar mysteries in other giant and supergiant stars.
现在，从我们的角度来看，参宿四正在让它的伴星黯然失色，天文学家正在计划对其下一次出现在 2027 年进行新的观测。这一突破也可能有助于解释其他巨星和超巨星中的类似谜团。
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
哈勃太空望远镜已经运行了三十多年，并不断做出突破性的发现，塑造我们对宇宙的基本理解。哈勃望远镜是 NASA 和 ESA（欧洲航天局）之间的国际合作项目。美国宇航局位于马里兰州格林贝尔特的戈达德太空飞行中心负责管理望远镜和任务操作。总部位于丹佛的洛克希德·马丁航天公司也支持戈达德的任务运营。位于巴尔的摩的太空望远镜科学研究所由天文学研究大学协会运营，为美国宇航局进行哈勃科学操作。