--- title: "Scientists Find Gigantic Planet a Quarter the Size of Its Star" description: "Astronomers have discovered a highly unusual \"forbidden\" gas giant exoplanet, which is so big, it defies our current models." date: "2023-02-24" modified: "2023-02-24" authors: - name: "Victor Tangermann" job_title: "Senior Editor" link: "https://futurism.com/authors/victor" url: "https://futurism.com/the-byte/scientists-gigantic-planet-quarter-size-star" categories: - "Off-World" - "Space" tags: - "Exoplanets" - "gas giants" - "the digest" --- # Scientists Find Gigantic Planet a Quarter the Size of Its Star ![Astronomers have discovered a highly unusual "forbidden" gas giant exoplanet, which is so big, it defies our current models.]() *\Image: Katherine Cain/Carnegie Institution for Science\* ## Gigantic Gas Giant Astronomers at the Carnegie Institution for Science [have discovered]() a highly unusual "forbidden" gas giant exoplanet — a cosmic monster so comically gigantic, at a quarter the size of its host star, that it defies our current classification system. The baffling discovery could even challenge what we know about how planets are formed. "Based on our nominal current understanding of planet formation, TOI-5205b should not exist; it is a 'forbidden' planet," said Shubham Kanodia, team lead, and Carnegie astronomer, in a [statement](). ## Size XXL As detailed in a [new paper]() published in *The Astronomical Journal*, the planet in question orbits a tiny red dwarf star called TOI-5205, one of the most common types of stars in our galaxy. While these hot and long-lasting stars are known to host planets, they're typically unlikely to host gas giants of any considerable size. But the researchers' discovery, the star's gas giant dubbed TOI 5205b, is simply far bigger than it ought to be, at roughly a quarter the size of its host star. The researchers were taken aback by the planet, first identified by NASA's Transiting Exoplanet Survey Satellite (TESS). "The host star, TOI-5205, is just about four times the size of Jupiter, yet it has somehow managed to form a Jupiter-sized planet, which is quite surprising!" said Kanodia in a statement. ![]() *Katherine Cain, courtesy of the Carnegie Institution for Science* ## Blocking Light It's not the first gas giant to have been discovered orbiting a red dwarf star of this size. But TOI-5025b is simply far bigger than anything found previously, defying our existing models. In fact, it blocks a whopping seven percent of its star when passing in front of it, which also happens to make it the perfect candidate to be observed by NASA's James Webb Space Telescope. "TOI-5205b’s existence stretches what we know about the disks in which these planets are born," Kanodia said. "In the beginning, if there isn’t enough rocky material in the disk to form the initial core, then one cannot form a gas giant planet." "And at the end, if the disk evaporates away before the massive core is formed, then one cannot form a gas giant planet," he added. **READ MORE:** [“Forbidden” planet orbiting small star challenges gas giant formation theories]() \[Carnegie\] **More on planets:** *[NASA Scientist Calls for Exploration of Uranus]()* ## Author I've been at Futurism since 2017, where my role has evolved to encompass design, writing, and increasingly editing. I've always been fascinated by space exploration and advanced transportation, which I've leaned into by interviewing luminaries in those fields while closely following the dimensions of policy and regulation that allow next-generation projects to succeed -- or, sometimes, to fail. I'm also keenly interested in the effects of generative AI on society, policies, and democratic institutions, as well as clean energy, physics and biology, and the vagaries of tech leadership. My work for Futurism has been cited by publications including Ars Technica, Gizmodo, PC Magazine, Jalopnik, Fox News, and the New York Post. I spent my childhood living in locations including Manila, the Philippines, and Geneva, Switzerland, attended McGill University, and now live in Toronto, Canada. Before Futurism I worked at AskMen and a small photography studio. In my free time, I'm an avid gardener, foodie, and craft beer lover, as well as a maker of artisanal hot pepper sauces. I have a magnificent dog named Freida. ### Author social links [Bluesky]()