{"id":421852,"date":"2026-01-20T17:39:12","date_gmt":"2026-01-20T17:39:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/421852\/"},"modified":"2026-01-20T17:39:12","modified_gmt":"2026-01-20T17:39:12","slug":"hubble-observations-add-evidence-of-elusive-companion-orbiting-supergiant-star-betelgeuse","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/421852\/","title":{"rendered":"Hubble observations add evidence of elusive companion orbiting supergiant star Betelgeuse"},"content":{"rendered":"

\n Astronomers have long searched for clues that a hidden companion star sits out of view near the red supergiant star Betelgeuse<\/a>. Now, they\u2019ve uncovered a new piece of evidence: a trail like the wake behind a boat, cutting through Betelgeuse\u2019s upper atmosphere, likely forged by the unseen companion.\n <\/p>\n

\n Betelgeuse\u2019s reddish tint can be spotted gleaming from the Orion constellation, situated about 650 light-years away from Earth.\n <\/p>\n

\n The bright star is so large that more than 400 million suns could fit inside of it. Its relative proximity and luminosity have made it a favorite among astronomers who observe and study the giant star\u2019s evolution.\n <\/p>\n

\n Yet, despite being so well known, Betelgeuse has its share of secrets \u2014 one of the biggest being why it appears to vary in brightness over a six-year cycle, and if the unseen stellar companion, nicknamed \u201cBetelbuddy,\u201d is responsible for this variability.\n <\/p>\n

\n Hints about the possible companion star were shared in research published last year<\/a>, in which scientists suggested formally naming the object Siwarha<\/a>, or \u201cher bracelet,\u201d an Arabic name befitting the companion to Betelgeuse, which means \u201cHand of the Giant.\u201d (\u201cElgeuse\u201d is also the historic Arabic name of the Orion constellation.)\n <\/p>\n

\n Siwarha would likely be too small and faint to be seen given its proximity to Betelgeuse, which has expanded as it has burned through all the hydrogen at its core, bringing it near the end of its life.\n <\/p>\n

\n Now, observations taken over the last eight years have revealed the effects of Siwarha on Betelgeuse: a never-before-seen dense trail of gas spotted moving through the larger star\u2019s outer atmosphere, where Siwarha closely orbits.\n <\/p>\n

\n Siwarha\u2019s trail appeared just after the star crossed in front of Betelgeuse from Earth\u2019s perspective. Astronomers believe Siwarha completes one orbit around Betelgeuse every six years \u2014 hence the larger star\u2019s change in brightness every six years. The observations are included in a new study<\/a> that has been accepted for publication in the Astrophysical Journal.\n <\/p>\n

\n \u201cIt\u2019s a bit like a boat moving through water. The companion star creates a ripple effect in Betelgeuse\u2019s atmosphere that we can actually see in the data,\u201d said lead study author Andrea Dupree, an astronomer at the Harvard-Smithsonian Center for Astrophysics, in a statement.\n <\/p>\n

\n \u201cFor the first time, we\u2019re seeing direct signs of this wake, or trail of gas, confirming that Betelgeuse really does have a hidden companion shaping its appearance and behavior.\u201d\n <\/p>\n

\n Betelgeuse is about 15 times the mass of our sun and 1,400 times bigger in diameter, Dupree said. Meanwhile, Siwarha is tiny and might be smaller than our sun.\n <\/p>\n

\n \u201cIf you placed Betelgeuse at the center of our solar system, the surface would extend to Jupiter and the hot atmosphere above it would extend at least 6 times further out,\u201d Dupree said. \u201cSo the companion is really plowing through a dense atmosphere of the supergiant star.\u201d\n <\/p>\n

\n Dupree\u2019s team has been tracking changes in Betelgeuse\u2019s light for years, using the Hubble Space Telescope<\/a> as well as ground-based observatories like the Fred Lawrence Whipple Observatory and Roque de Los Muchachos Observatory.\n <\/p>\n

\n Patterns emerged in the observations, captured both close to the star and further away from it, that suggested a companion star was whirling through Betelgeuse\u2019s extended atmosphere. The team recorded shifts in the speed and direction of gases in the large star\u2019s outer atmosphere due to a disturbance.\n <\/p>\n

\"A<\/p>\n

\n Hubble enabled the team to see how Betelgeuse\u2019s deep atmosphere, or chromosphere, reacted to Siwarha\u2019s motion, while the ground-based observations revealed changes in the extended atmosphere.\n <\/p>\n

\n \u201cWhat we learn from these latest results is that Siwarha seems to \u2018stir up\u2019 Betelgeuse\u2019s extended atmosphere as it orbits, leaving a wake that impacts what we see from Betelgeuse itself,\u201d said study coauthor Morgan MacLeod, a postdoctoral fellow in theoretical astrophysics and member of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics.\n <\/p>\n

\n \u201cThis wake is evidence of Siwarha\u2019s presence and it\u2019s also a trace of how such a small companion is able to affect what we see of Betelgeuse, by modulating the gas and dust around it,\u201d he added.\n <\/p>\n

\n The results add support to findings<\/a> about Siwarha made by Steve Howell and his team in 2025. Howell is a senior research scientist at NASA Ames Research Center in California.\n <\/p>\n

\n His team\u2019s observations suggested that the detected size of Siwarha also included a larger region around it as it plowed through Betelgeuse\u2019s atmosphere.\n <\/p>\n

\n \u201cThe idea of some expanding plasma wake surrounding Siwarha would seem to agree with our finding of a larger, blobby source and not just a naked stellar photosphere,\u201d Howell said. He was not involved in the new study.\n <\/p>\n

\n Tracking Betelgeuse\u2019s behavior and variations can help astronomers better understand other, faint and distant giant stars that are difficult to study, MacLeod said.\n <\/p>\n

\n But in recent years, Betelgeuse has thrown astronomers a few puzzling curveballs that have required serious detective work to solve.\n <\/p>\n

\n From late 2019 to the beginning of 2020, Betelgeuse dimmed so sharply that experts thought the star was on the brink of exploding in a supernova. Since the event, called the \u201cGreat Dimming<\/a>,\u201d teams of astronomers have determined that the star ejected a large dust cloud, which temporarily blocked some of its light from Earth\u2019s perspective.\n <\/p>\n

\n Additionally, the star has exhibited two regular variations in luminosity: the six-year period, as well as a cycle that lasts a little over a year.\n <\/p>\n

\n Data collected over years have shown that Betelgeuse\u2019s luminosity varies about every 416 days, growing fainter and then brighter. This pulsation, which occurs within Betelgeuse\u2019s core, was found to be typical of red supergiant stars.\n <\/p>\n

\n The longer 2,100-day period was thought to be due to dust clouds, large convection cells on the star, magnetic activity or an elusive companion star always out of the optical reach of telescopes.\n <\/p>\n

\n Within the last year, evidence from multiple research teams has pointed to the reason being the presence of Siwarha.\n <\/p>\n

\n \u201cWith this new direct evidence, Betelgeuse gives us a front-row seat to watch how a giant star changes over time,\u201d Dupree said. \u201cFinding the wake from its companion means we can now understand how stars like this evolve, shed material, and eventually explode as supernovae.\u201d\n <\/p>\n

\n Other supergiant stars that also display similar patterns of long and short variability may also have invisible companions, Dupree added.\n <\/p>\n

\n Jared Goldberg, a research fellow at the Flatiron Institute\u2019s Center for Computational Astrophysics, believes the new observations are an important piece of the puzzle in understanding what causes Betelgeuse\u2019s six-year variability. Goldberg previously authored research about the companion star<\/a>, but was not involved in this study.\n <\/p>\n

\n If astronomers can conclude that periodic variability is due to the presence of a second star, \u201cwe can make direct connections to the physics behind formation and evolution of both stars and planets,\u201d Goldberg said.\n <\/p>\n

\n The team is also working on hydrodynamic models to determine how the wake forms behind Siwarha and reconstruct how that effects Betelgeuse\u2019s brightness, MacLeod said.\n <\/p>\n

\n A hydrodynamic analysis would provide the vital information needed to interpret the new observations, such as what to expect from the motion of a solar-size companion moving through the outer atmosphere of a huge red supergiant, said Edward Guinan, professor of astronomy and astrophysics at Villanova University in Pennsylvania. Guinan has studied Betelgeuse but was not involved in the new research.\n <\/p>\n

\n With Siwarha in such close proximity to Betelgeuse, what is the smaller star\u2019s fate?\n <\/p>\n

\n MacLeod believes Siwarha is being drawn increasingly closer to its massive companion due to gravitational forces, which could result in a merger within 9,000 years.\n <\/p>\n

\n \u201cWe think the stars might merge even before Betelgeuse goes supernova,\u201d MacLeod said. \u201cThis would splash out some gas, spin up Betelgeuse and potentially affect the properties of the eventual supernova.\u201d\n <\/p>\n

\n Based on astronomers\u2019 calculations, Siwarha is now on the far side of Betelgeuse relative to Earth\u2019s telescopes, but it is expected to emerge into view in 2027.\n <\/p>\n

\n \u201cFurther detections will allow refinements to its orbit and thus give a better mass of Siwarha, helping to explain the evolution of the binary system, Betelgeuse\u2019s rapid rotation, and the future of the two stars,\u201d Howell said.\n <\/p>\n

\n Multiple teams are hoping to find a way to detect Siwarha optically.\n <\/p>\n

\n \u201cSeeing the companion will be the ultimate proof of its implied existence,\u201d Guinan said. \u201cI can\u2019t wait.\u201d\n <\/p>\n

\n Sign up for CNN\u2019s Wonder Theory science newsletter<\/a>. Explore the universe with news on fascinating discoveries, scientific advancements and more.<\/p>\n","protected":false},"excerpt":{"rendered":"Astronomers have long searched for clues that a hidden companion star sits out of view near the red…\n","protected":false},"author":2,"featured_media":421853,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[49,48,66,306],"class_list":["post-421852","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-ca","tag-canada","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/421852","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=421852"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/421852\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/421853"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=421852"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=421852"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=421852"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}