{"id":228908,"date":"2026-01-13T05:25:14","date_gmt":"2026-01-13T11:25:14","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2026\/01\/the-dark-halo-that-never-lit-up"},"modified":"2026-01-13T05:25:14","modified_gmt":"2026-01-13T11:25:14","slug":"the-dark-halo-that-never-lit-up","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2026\/01\/the-dark-halo-that-never-lit-up","title":{"rendered":"The Dark Halo That Never Lit Up"},"content":{"rendered":"

<\/a><\/p>\n

Galaxies announce themselves through the light of billions of stars, all embedded in vast clumps, or \u201chalos,\u201d of dark matter. But researchers may have spotted, for the first time, a starless halo of dark matter\u2014containing only a gas cloud. The result was announced by Rachael Beaton of the Space Telescope Science Institute in Maryland at the meeting of the American Astronomical Society<\/a> in Phoenix, Arizona. Using observations from the Hubble Space Telescope, Beaton and her collaborators showed that the object, known as Cloud-9, contains a negligible amount of stars [1<\/a>]. \u201cThere is nothing like this that we have found so far in the Universe,\u201d Beaton said in a press conference last week.<\/p>\n

Cloud-9\u2019s makeup\u2014as inferred from radio and optical observations\u2014would qualify it as the first example of a REionization-Limited H I Cloud (RELHIC), a starless dark matter halo filled with neutral hydrogen gas (H I). RELHICs are thought to be leftovers of dark matter clumps that couldn\u2019t accrue a sufficient amount of gas to form stars, says the project\u2019s principal investigator Alejandro Ben\u00edtez-Llambay of the University of Milano-Bicocca in Italy. A RELHIC is \u201ca tale of a failed galaxy,\u201d he says.<\/p>\n

Starless halos arise naturally within the standard paradigm of cosmology: the lambda cold dark matter (\u039bCDM) model, where \u039b refers to a \u201ccosmological constant\u201d that describes dark energy. According to \u039bCDM, dark matter can cluster into halos that provide the gravitational backbone for galaxy formation. The model also predicts that there is a critical mass below which halos would be too small to ever form stars. Spotting unlit halos might sound hopeless, but simulations by Ben\u00edtez-Llambay and collaborators in 2017 suggested that halos within a narrow mass range may exist as RELHICs (a term they coined) [2<\/a>]. According to their calculations, RELHICs would have masses close to the critical value for galaxy formation. Crucially, the compact, hydrogen-filled cores of these objects provide a potential observational window, since hydrogen clouds have a characteristic radio emission.<\/p>\n","protected":false},"excerpt":{"rendered":"

Galaxies announce themselves through the light of billions of stars, all embedded in vast clumps, or \u201chalos,\u201d of dark matter. But researchers may have spotted, for the first time, a starless halo of dark matter\u2014containing only a gas cloud. The result was announced by Rachael Beaton of the Space Telescope Science Institute in Maryland at [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33,1617],"tags":[],"class_list":["post-228908","post","type-post","status-publish","format-standard","hentry","category-cosmology","category-quantum-physics"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/228908","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=228908"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/228908\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=228908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=228908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=228908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}