{"id":27427,"date":"2025-08-08T16:12:28","date_gmt":"2025-08-08T10:27:28","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=27427"},"modified":"2025-08-08T16:12:30","modified_gmt":"2025-08-08T10:27:30","slug":"webb-finds-new-evidence-for-planet-around-closest-solar-twin","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/webb-finds-new-evidence-for-planet-around-closest-solar-twin\/","title":{"rendered":"Webb finds new evidence for planet around closest solar twin"},"content":{"rendered":"\n
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Alpha Centauri A and Planet (Artist\u2019s Concept), Image Credit: NASA, ESA, CSA, STScI, R. Hurt (Caltech\/IPAC)<\/sup><\/em><\/figcaption><\/figure>\n\n\n\n

Astronomers have found strong evidence of a giant planet orbiting a star in the stellar system closest to our own Sun. At just 4 light-years away from Earth, the Alpha Centauri triple star system has long been a compelling target in the search for worlds beyond our solar system.<\/p>\n\n\n\n

Visible only from Earth\u2019s Southern Hemisphere, it\u2019s made up of the binary Alpha Centauri A and Alpha Centauri B, both Sun-like stars, and the faint red dwarf star Proxima Centauri. Alpha Centauri A is the third brightest star in the night sky. While there are three confirmed planets orbiting Proxima Centauri, the presence of other worlds surrounding Alpha Centauri A and Alpha Centauri B has proved challenging to confirm.<\/p>\n\n\n\n

Now, Webb\u2019s observations from its Mid-Infrared Instrument (MIRI<\/a>) are providing the strongest evidence to date of a gas giant orbiting Alpha Centauri A. The results have been accepted in a series of two papers in The Astrophysical Journal Letters.<\/p>\n\n\n\n

If confirmed, the planet would be the closest to Earth that orbits in the habitable zone<\/a> of a Sun-like star. However, because the planet candidate is a gas giant, scientists say it would not support life as we know it.<\/p>\n\n\n\n

\u201cWith this system being so close to us, any exoplanets found would offer our best opportunity to collect data on planetary systems other than our own. Yet, these are incredibly challenging observations to make, even with the world\u2019s most powerful space telescope, because these stars are so bright, close, and move across the sky quickly,\u201d said Charles Beichman, NASA\u2019s Jet Propulsion Laboratory and the NASA Exoplanet Science Institute at Caltech\u2019s IPAC astronomy center, co-first author on the new papers.<\/p>\n\n\n\n

\u201cWebb was designed and optimized to find the most distant galaxies in the universe. The operations team at the Space Telescope Science Institute had to come up with a custom observing sequence just for this target, and their extra effort paid off spectacularly.\u201d\u00a0<\/p>\n\n\n\n

Several rounds of meticulously planned observations by Webb, careful analysis by the research team, and extensive computer modeling helped determine that the source seen in Webb\u2019s image is likely to be a planet and not a background object (like a galaxy), foreground object (a passing asteroid), or other detector or image artifact.\u00a0<\/p>\n\n\n\n

The first observations of the system took place in August 2024, using the coronagraphic mask aboard MIRI to block Alpha Centauri A\u2019s light. While extra brightness from the nearby companion star Alpha Centauri B complicated the analysis, the team was able to subtract out the light from both stars to reveal an object over 10,000 times fainter than Alpha Centauri A, separated from the star by about two times the distance between the Sun and Earth. <\/p>\n\n\n\n

While the initial detection was exciting, the research team needed more data to come to a firm conclusion. However, additional observations of the system in February 2025 and April 2025 (using Director\u2019s Discretionary Time) did not reveal any objects like the one identified in August 2024.<\/p>\n\n\n\n

\u201cWe are faced with the case of a disappearing planet! To investigate this mystery, we used computer models to simulate millions of potential orbits, incorporating the knowledge gained when we saw the planet, as well as when we did not,\u201d\u00a0said PhD student Aniket Sanghi of the California Institute of Technology in Pasadena, California. Sanghi is a co-first author on the two papers covering the team\u2019s research.<\/p>\n\n\n\n

In these simulations, the team took into account both the 2019 sighting of a potential exoplanet candidate by the European Southern Observatory\u2019s Very Large Telescope<\/a>, the new data from Webb, and considered orbits that would be gravitationally stable in the presence of Alpha Centauri B, meaning the planet wouldn\u2019t get flung out of the system. <\/p>\n\n\n\n

Researchers say a non-detection in the second and third rounds of observations with Webb isn\u2019t surprising.<\/p>\n\n\n\n

\u201cWe found that in half of the possible orbits simulated, the planet moved too close to the star and wouldn\u2019t have been visible to Webb in both February and April 2025,\u201d\u00a0said Sanghi.\u00a0<\/p>\n\n\n\n

Based on the brightness of the planet in the mid-infrared observations and the orbit simulations, researchers say it could be a gas giant approximately the mass of Saturn orbiting Alpha Centauri A in an elliptical path varying between 1 to 2 times the distance between the Sun and Earth.\u00a0<\/p>\n\n\n\n

\u201cThese are some of the most demanding observations we’ve done so far with MIRI’s coronagraph,\u201d said Pierre-Olivier Lagage, of CEA, France, who is a co-author on the papers and was the French lead for the development of MIRI. “When we were developing the instrument, we were eager to see what we might find around Alpha Centauri, and I’m looking forward to what it will reveal to us next!”\u00a0<\/p>\n\n\n\n

\u00a0“If confirmed, the potential planet seen in the Webb image of Alpha Centauri A would mark a new milestone for exoplanet imaging efforts,”\u00a0Sanghi says.\u00a0“Of all the directly imaged planets, this would be the closest to its star seen so far. It’s also the most similar in temperature and age to the giant planets in our solar system, and nearest to our home, Earth,”\u00a0he says.<\/p>\n\n\n\n

“Its very existence in a system of two closely separated stars would challenge our understanding of how planets form, survive, and evolve in chaotic environments.”\u00a0<\/p>\n\n\n\n

If confirmed by additional observations, the team\u2019s results could transform the future of exoplanet science. <\/p>\n\n\n\n

\u201cThis would become a touchstone object for exoplanet science, with multiple opportunities for detailed characterization by Webb and other observatories,\u201d\u00a0said Beichman.<\/p>\n","protected":false},"excerpt":{"rendered":"

Astronomers have found strong evidence of a giant planet orbiting a star in the stellar system closest to our own Sun.<\/p>\n","protected":false},"author":2,"featured_media":27428,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-27427","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-space-news"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-200x200.webp",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-675x276.webp",675,276,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-600x300.webp",600,300,true],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-600x300.webp",600,300,true],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin.webp",733,300,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-550x300.webp",550,300,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-95x65.webp",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-640x300.webp",640,300,true],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-96x96.webp",96,96,true],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/solar-twin-150x61.webp",150,61,true]},"author_info":{"info":["RevoScience"]},"category_info":"Space\/ AstroPhysics<\/a>","tag_info":"Space\/ AstroPhysics","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27427","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=27427"}],"version-history":[{"count":2,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27427\/revisions"}],"predecessor-version":[{"id":27430,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27427\/revisions\/27430"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/27428"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=27427"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=27427"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=27427"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}