{"id":622244,"date":"2026-10-06T12:02:07","date_gmt":"2026-10-06T12:02:07","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/622244\/"},"modified":"2026-10-06T12:02:07","modified_gmt":"2026-10-06T12:02:07","slug":"alma-reveals-a-strange-hotspot-on-betelgeuse","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/622244\/","title":{"rendered":"ALMA Reveals a Strange Hotspot on Betelgeuse"},"content":{"rendered":"

Betelgeuse, the fiery-orange beacon in Orion\u2019s shoulder, has long fascinated astronomers. It\u2019s a red supergiant<\/a> nearly 800 times larger than our Sun, and one of the closest of its kind, sitting just 600 light-years away.<\/p>\n

Unlike the Sun\u2019s smooth, round surface, Betelgeuse looks lumpy and uneven, its atmosphere bubbling with giant convective cells that churn hot gas to the surface.<\/p>\n

Now, new high-resolution images from the Atacama Large Millimeter\/submillimeter Array (ALMA) have given us one of the most detailed views yet of this colossal star\u2019s surface. And what they reveal is both expected and surprising.<\/p>\n

Astronomers found two distinct \u201chot patches\u201d on Betelgeuse\u2019s surface<\/a>, one to the northeast and another to the southwest. The brightest of these is about 800 degrees hotter than the surrounding photosphere. Remarkably, this hotspot appears almost unchanged compared to similar ALMA data taken seven years earlier.<\/p>\n

Hubble discovered the cause of mysterious dimming of supergiant star Betelgeuse<\/a><\/p>\n

The model of convection for red giant stars states that these types of features will be of short duration; they will last from one month to possibly a couple of years. The long-term presence of this hot spot indicates that there may be something unique happening. This may relate to stable convection in the polar regions, or it may relate to the effects of a companion star (indicated by other telescopic data).<\/p>\n

The new ALMA data show Betelgeuse\u2019s sub-millimeter photosphere has a radius about 1.1\u20131.3 times the star\u2019s size, with a relatively constant temperature of ~2300 K. But it isn\u2019t perfectly round. Deviations of up to 6% in radius make the star\u2019s edge look irregular, with clumpy gas extending out to about 2.5 times the stellar radius.<\/p>\n

It is believed that these irregularities are due to shocks created by convection; however, how long they last is contrary to our current understanding of stellar behavior.<\/p>\n

Betelgeuse isn\u2019t just any star; it\u2019s a supergiant nearing the end of its life. In 2020, it famously dimmed, sparking speculation that it was about to explode. While that wasn\u2019t the case, astronomers are keen to understand how surface activity and hotspots might relate to such dramatic events.<\/p>\n

ESO Telescope Sees Surface of Dim Betelgeuse<\/a><\/p>\n

\u201cIts eventual fate as a supernova makes it fascinating to know what it actually looks like now,\u201d says lead author Bill Dent, an astronomer at ESO. When Betelgeuse does finally explode, it will shine so brightly that it will be visible from Earth even in daylight.<\/p>\n

The new observations confirm that stars do not remain still as if they were solid objects; rather, they are dynamic and active environments. The hotspots, bumps, and clumps on the surface of Betelgeuse illustrate how massive stars lose matter<\/a> to the space surrounding them, and therefore enrich the interstellar medium with elements which can ultimately create planets and possibly life.<\/p>\n

Journal Reference:<\/p>\n

W.R.F. Dent, A.M.S. Richards, G.M. Harper, L.D. Matthews, E. O\u2019Gorman. ALMA high-resolution observations of Betelgeuse: Persistent structure spanning the inner atmosphere. Astronomy & Astrophysics. DOI: 10.48550\/arXiv.2608.19339<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Betelgeuse, the fiery-orange beacon in Orion\u2019s shoulder, has long fascinated astronomers. It\u2019s a red supergiant nearly 800 times…\n","protected":false},"author":2,"featured_media":622245,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[47350,111,139,69,147,5436],"class_list":["post-622244","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-alma","tag-new-zealand","tag-newzealand","tag-nz","tag-science","tag-stars"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/622244","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=622244"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/622244\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/622245"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=622244"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=622244"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=622244"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}