{"id":743197,"date":"2026-06-17T17:47:09","date_gmt":"2026-06-17T17:47:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/743197\/"},"modified":"2026-06-17T17:47:09","modified_gmt":"2026-06-17T17:47:09","slug":"new-supernova-study-confirms-universes-expansion-is-still-accelerating","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/743197\/","title":{"rendered":"New Supernova Study Confirms Universe\u2019s Expansion is Still Accelerating"},"content":{"rendered":"

A fresh analysis of Type Ia supernovae overturns a controversial 2025 claim that cosmic expansion is slowing.<\/p>\n

\"Type<\/p>\n

Type Ia supernovae are a cornerstone of modern cosmology, providing first evidence for cosmic acceleration and new tests of dark energy. Image credit: Alex Parker \/ NASA \/ SDSS.<\/p>\n

In 2025, Yonsei University\u2019s Professor Young-Wook Lee and colleagues shocked the space community with claims<\/a> that the evidence of dark energy was weakening such that the expansion is no longer accelerating.<\/p>\n

They suggested the methods used to measure the Universe\u2019s expansion using supernovae were fundamentally flawed.<\/p>\n

\u201cThe debate that followed last year\u2019s revelations was the result of a scientific misunderstanding rather than a flaw in the Universe itself,\u201d said University of Southampton\u2019s Dr. Phil Wiseman, first author of the new study.<\/p>\n

\u201cThe previous and well accepted measurements were, in fact, fine and our current understanding of the fate of the Universe remains robust.\u201d<\/p>\n

\u201cThankfully we have averted this crisis, but the mystery about why the Universe is still accelerating in size remains.\u201d<\/p>\n

\u201cBy proving our measurements are correct, we can get back to trying to understand what dark energy actually is, rather than wondering if it exists at all.\u201d<\/p>\n

The original discovery of the accelerating expansion of the Universe won<\/a> the Nobel Prize in Physics in 2011.<\/p>\n

If the 2025 claims had been true, it would have dismantled nearly three decades of astronomical progress.<\/p>\n

\u201cExtraordinary claims require especially careful testing,\u201d said Nobel laureate Professor Adam Riess, co-author of the new study.<\/p>\n

\u201cWhat we find is that when we calibrate these supernovae, accounting for different host environments and populations, the evidence for cosmic acceleration remains remarkably consistent.\u201d<\/p>\n

To measure the Universe, the authors looked closely at Type Ia supernovae to calculate vast cosmic distances.<\/p>\n

The 2025 study had claimed that, as the Universe aged, these supernovae had different maximum brightnesses, tricking astronomers into thinking the cosmos was accelerating when it was slowing.<\/p>\n

However, the new study found the error lay in how the age of these stars was estimated.<\/p>\n

They proved that the previous findings incorrectly assumed the age of a galaxy was the same as the age of the star that exploded.<\/p>\n

They also said the 2025 paper failed to account for the mass of host galaxies, a standard correction used in modern cosmology to prove accuracy.<\/p>\n

\u201cChallenging accepted theories and observations is fundamental to science,\u201d said University of Southampton\u2019s Professor Mark Sullivan, co-author of the study.<\/p>\n

\u201cThis is how progress is made. Although this idea did not turn out correct, it has opened up new ways of thinking about how supernovae explode and how we can measure dark energy more accurately.\u201d<\/p>\n

\u201cWe\u2019ve recently been really focused on astrophysics of the explosions and how they impact cosmology,\u201d said study co-author Dr. Brodie Popovic, an astronomer at the University of Southampton.<\/p>\n

\u201cThis was a good opportunity to go back and go over all of our assumptions \u2014 it turns out, yes, we do understand this stuff and we\u2019re accounting for it in our cosmology measurement.\u201d<\/p>\n

The new study<\/a> appears in the Monthly Notices of the Royal Astronomical Society.<\/p>\n

_____<\/p>\n

Phil Wiseman et al. 2026. Still accelerating: Type Ia supernova cosmology is robust to host galaxy age evolution. MNRAS 549 (3): stag797; doi: 10.1093\/mnras\/stag797<\/p>\n","protected":false},"excerpt":{"rendered":"A fresh analysis of Type Ia supernovae overturns a controversial 2025 claim that cosmic expansion is slowing. Type…\n","protected":false},"author":2,"featured_media":743198,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[62291,49,48,41938,154774,66,44637,123188,831,266465],"class_list":["post-743197","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-acceleration","tag-ca","tag-canada","tag-dark-energy","tag-hubble-constant","tag-science","tag-supernova","tag-type-ia-supernova","tag-universe","tag-universes-expansion"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/743197","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=743197"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/743197\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/743198"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=743197"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=743197"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=743197"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}