{"id":477035,"date":"2026-02-19T03:14:07","date_gmt":"2026-02-19T03:14:07","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/477035\/"},"modified":"2026-02-19T03:14:07","modified_gmt":"2026-02-19T03:14:07","slug":"this-galaxy-is-99-dark-matter-and-basically-invisible","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/477035\/","title":{"rendered":"This Galaxy Is 99% Dark Matter\u2014and Basically Invisible"},"content":{"rendered":"

Dark matter doesn\u2019t emit, absorb, or reflect light. It\u2019s invisible but supposedly makes up 85% of the universe\u2019s mass. Because it\u2019s so abundant, astronomers believe it should explain many unsolved mysteries surrounding the cosmos, including an extraordinary dim galaxy \u201chiding\u201d in plain sight.<\/p>\n

Last summer, astronomers vetted candidates for so-called dark galaxies, or a rare class of galaxies with remarkably low surface brightness. The paper on the findings, published in The Astrophysical Journal Letters<\/a>, surmised that so-called \u201cdark galaxies\u201d should have \u201csome of the most extreme properties among all known galaxies.\u201d<\/p>\n

And today, NASA shared high-resolution images of one such galaxy, CDG-2. If the astronomers\u2019 hypothesis is correct, CDG-2 would be among the most heavily dark-matter-filled galaxies ever identified.<\/p>\n

\u201cSeeing\u201d the invisible <\/p>\n

Again, dark matter doesn\u2019t interact with light. However, astronomers infer its presence from dark matter\u2019s gravitational influence on surrounding objects. Often, this refers to unseen mass that seems to be driving galaxies, planets, stars, and supernovas\u2014you name it\u2014to appear a certain way.<\/p>\n

Simply put, if dark matter didn\u2019t exist, many of the models scientists use to understand the cosmos would break down. Although scientists have yet to directly detect dark matter, dissenters have also yet to find an alternative that explains things better. So the consensus, at least for now, is that dark matter exists.<\/p>\n<\/p>\n

Hints of an invisible galaxy <\/p>\n

CDG-2 lies within the Perseus galaxy cluster, a section of the universe filled with globular clusters, or tightly bound units filled with millions of stars. Accordingly, this neighborhood is known for its particularly rich population of densely packed stars.<\/p>\n

Then, Hubble noticed a close collection of four globular clusters among the bunch. When Hubble, ESA\u2019s Euclid<\/a>, and the Subaru Telescope<\/a> in Hawaii collectively took a closer look, astronomers noticed a faint glow circling the area\u2014leading them to wonder if the whole thing was actually just one galaxy.<\/p>\n

\"CdgThe circle marked with a dashed red boundary indicates the location of the dark-matter-dominated galaxy. Within the red, dashed circle are four globular clusters outlined by small, blue circles. Credit: NASA\/ESA\/Dayi Li (UToronto)\/Joseph DePasquale (STScI) <\/p>\n

The researchers behind the study conducted a statistical analysis of the galaxy, finding that the four clusters likely are part of a single galaxy\u2014and a dark one at that.<\/p>\n

\u201cThis is the first galaxy detected solely through its globular cluster population,\u201d David Li, the study\u2019s lead author and an astronomer at the University of Toronto, said in a NASA release<\/a>.<\/p>\n

A crowded neighborhood <\/p>\n

According to the researchers, CDG-2 has a luminosity equivalent to roughly 6 million Sun-like stars, with the globular clusters contributing around 16% of that total. In terms of mass, however, 99% of the galaxy\u2019s mass appears to be dark matter.<\/p>\n

The \u201cnormal\u201d matter in CDG-2\u2014primarily hydrogen gas for star formation\u2014was likely stripped away by the dense population of galaxies inside the Perseus cluster, the scientists said. But even if CDG-2 isn\u2019t necessarily a dark galaxy, it\u2019s still an odd one, the researchers said, and would be an ideal candidate to study and test theories on clustered star formation and its potential implications, according to the paper.<\/p>\n

Either way, it looks like astronomers have no shortage of things they\u2019re counting on dark matter to prove.<\/p>\n","protected":false},"excerpt":{"rendered":"Dark matter doesn\u2019t emit, absorb, or reflect light. It\u2019s invisible but supposedly makes up 85% of the universe\u2019s…\n","protected":false},"author":2,"featured_media":477036,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[49],"tags":[10240,199,79],"class_list":{"0":"post-477035","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-galaxies","9":"tag-physics","10":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/477035","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=477035"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/477035\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/477036"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=477035"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=477035"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=477035"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}