This Is the Most Detailed Image Yet of the Milky Way’s Center

这是迄今为止银河系中心最详细的图像

The European Space Agency’s (ESA) Euclid space telescope has captured the largest and most detailed visible-light image ever obtained of the Milky Way’s galactic bulge, the central region of our galaxy. 欧洲航天局（ESA）的欧几里得（Euclid）空间望远镜拍摄了迄今为止银河系核球（即我们银河系的中心区域）最大、最详细的可见光图像。

The image is a mosaic containing more than 60 million stars, as well as nebulae and star clusters. It will allow scientists to confirm the possible presence of exoplanets using a microlensing technique and measure their masses with greater precision. 这张图像是一幅包含超过 6000 万颗恒星以及星云和星团的马赛克拼图。它将使科学家能够利用微引力透镜技术确认系外行星的存在，并更精确地测量它们的质量。

The Power of Euclid

欧几里得的威力

Although Euclid was designed to observe billions of distant galaxies, its visible-light camera is sensitive enough to resolve individual stars at the center of the Milky Way—a region that is both extremely bright and densely populated—without being overwhelmed by the intense light. 尽管欧几里得的设计初衷是观测数十亿个遥远的星系，但其可见光相机极其灵敏，足以分辨出银河系中心（一个既极其明亮又高度密集的区域）的单颗恒星，且不会被强光淹没。

On March 23, 2025, Euclid turned its gaze toward the galactic bulge, capturing this enormous image in just 26 hours of observations. The result was remarkable: a mosaic composed of nine separate “pointings” (exposures) by its visible-light camera, each covering an area of sky larger than the full moon. 2025 年 3 月 23 日，欧几里得将目光投向银河系核球，仅用 26 小时的观测就捕捉到了这张巨大的图像。结果令人惊叹：这是一幅由其可见光相机拍摄的九个独立“指向”（曝光）组成的马赛克图，每个指向覆盖的天空面积都比满月还要大。

While the quality of Euclid’s visible-light images is comparable to that of the Hubble Space Telescope, there is one major difference: Each pointing that Euclid captures in just a few hours covers an area 270 times larger than Hubble’s field of view. It is also much faster. To put this into perspective, the Keck Observatory would require roughly 2,000 hours to observe the same mosaic. 虽然欧几里得的可见光图像质量与哈勃空间望远镜相当，但有一个主要区别：欧几里得在短短几小时内捕捉到的每个指向，其覆盖面积是哈勃视场的 270 倍。它的速度也快得多。为了对比，凯克天文台（Keck Observatory）需要大约 2000 小时才能观测到同样的马赛克区域。

The Image of the Milky Way

银河系的图像

The new Euclid image captures more than 60 million stars, along with nebulae and star clusters, in one of the Milky Way’s most crowded regions—a location ideally suited for searching for exoplanets through gravitational microlensing. 这张新的欧几里得图像捕捉到了银河系最拥挤区域之一的超过 6000 万颗恒星，以及星云和星团——这个位置非常适合通过引力微透镜技术搜寻系外行星。

“To catch microlensing, you need to observe parts of the sky that are crowded with stars, such as close to the centre of our galaxy,” said Jean-Philippe Beaulieu, who led the observing campaign, in a press release. “During the last 20 years, almost 300 exoplanets have been discovered using this technique, all with ground-based telescopes and all towards the center of our galaxy. This image from Euclid includes 51 known planetary systems—and it will assist in studying many more that will be found.” “要捕捉微引力透镜现象，你需要观测恒星密集的区域，例如靠近我们银河系中心的地方，”领导此次观测活动的让-菲利普·博利厄（Jean-Philippe Beaulieu）在新闻稿中表示。“在过去的 20 年里，利用这种技术已经发现了近 300 颗系外行星，它们全部是通过地面望远镜在银河系中心方向发现的。欧几里得的这张图像包含了 51 个已知的行星系统，它将有助于研究未来发现的更多行星。”

Measuring Planetary Masses

测量行星质量

Although detecting a microlensing event requires several weeks of observations—meaning Euclid could not identify any new events during its relatively short observational campaign—what makes this image so valuable is that it provides the data needed to measure the masses of already known planets, as well as planets that have yet to be discovered. 尽管探测微引力透镜事件需要数周的观测——这意味着欧几里得在其相对较短的观测活动中无法识别任何新事件——但这张图像的价值在于，它提供了测量已知行星以及尚未发现的行星质量所需的数据。

“In 24 hours, Euclid has already captured the stars involved in all the future microlensing events that the Roman space telescope will detect, but before the stars and planets involved have aligned,” said Natalia Rektsini, who led the publication of the data, in a press release. (The Nancy Grace Roman space telescope is slated to launch later this year.) “This means that anyone who detects a microlensing event in the same region, for example with Roman, will be able from now on to use Euclid data as a time reference in the past and see how the stars looked before they overlapped.” “在 24 小时内，欧几里得已经捕捉到了罗曼（Roman）空间望远镜未来将探测到的所有微引力透镜事件所涉及的恒星，而且是在这些恒星和行星对齐之前，”负责发布该数据的娜塔莉亚·雷克西尼（Natalia Rektsini）在新闻稿中说道。（南希·格蕾丝·罗曼空间望远镜计划于今年晚些时候发射。）“这意味着任何在同一区域探测到微引力透镜事件的人（例如使用罗曼望远镜），从现在起都可以将欧几里得的数据作为过去的时间参考，查看恒星在重叠之前的样子。”

In effect, Euclid’s observations will serve as a reference archive for future missions, enabling more detailed studies of exoplanets and more precise measurements of their masses. 实际上，欧几里得的观测结果将作为未来任务的参考档案，从而实现对系外行星更详细的研究和更精确的质量测量。

“In just 24 hours, Euclid has delivered unique data on the Milky Way’s center, with a large and sharp view of this region,” said Valeria Pettorino, ESA’s Euclid project scientist, in a press release. “This data can also be used for other scientific applications, from brown dwarfs and binary stars to stellar motions and dust across our galaxy.” “在短短 24 小时内，欧几里得提供了关于银河系中心的独特数据，呈现了该区域广阔而清晰的视野，”欧空局欧几里得项目科学家瓦莱里娅·佩托里诺（Valeria Pettorino）在新闻稿中表示。“这些数据还可以用于其他科学应用，从褐矮星和双星，到整个银河系的恒星运动和尘埃研究。”

This story originally appeared on WIRED Italia and has been translated from Italian. 本文最初发表于《连线》意大利版，由意大利语翻译而来。