Picture this: Aging stars, once vibrant like our Sun, ballooning into colossal red giants and mercilessly gulping down their orbiting worlds. It's a cosmic drama unfolding right before our eyes, and new findings reveal the devastating toll on planetary systems. Intrigued? Keep reading to dive deeper into this stellar showdown.
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- Red giant stars represent the twilight phase of stellar life, where former sun-like entities have dramatically expanded in size. But can their planetary companions endure this transformation?
- For eons, scientists have predicted that red giants would obliterate planets orbiting too near. Fresh evidence now corroborates this grim outcome.
- Planetary bodies are far scarcer around red giants—particularly the more aged ones—indicating that the majority have already perished in these stellar engulfments.
The Fateful End for Planetary Companions of Aging Stars
Do elderly stars obliterate the worlds closest to them? Experts have long understood that stars akin to our Sun eventually bloat into red giants (https://earthsky.org/astronomy-essentials/what-are-red-giants-definition/) as death approaches. It's been theorized that exoplanets (https://earthsky.org/astronomy-essentials/what-are-exoplanets) in tight orbits would be swallowed whole. On November 5, 2025, scientists from University College London and the University of Warwick in the UK unveiled compelling proof (https://ras.ac.uk/news-and-press/research-highlights/ageing-stars-may-be-destroying-their-closest-planets) backing this idea. They examined almost 500,000 red giant stars and discovered that exoplanets are significantly rarer among these swollen stars, especially the elder ones, compared to other stellar types. This implies that numerous planets—especially those in proximate orbits—have likely been annihilated already.
Drawing from NASA's Transiting Exoplanet Survey Satellite (TESS (https://science.nasa.gov/mission/tess/)), the team pinpointed 130 confirmed planets and potential candidates. Among these, 33 were novel discoveries previously undetected.
Their peer-reviewed (https://ras.ac.uk/journals/editorial-policies) results appeared in the Monthly Notices of the Royal Astronomical Society on October 15, 2025 (https://academic.oup.com/mnras/article/544/1/1186/8286899).
Data shows a scarcity of large planets in close orbits around evolving stars, hinting that many are eliminated as their parent stars grow and mature.
— Science X / Phys.org (@sciencex.bsky.social) (https://bsky.app/profile/did:plc:ipnqgjcngbafxdo3bv3gamrx?refsrc=embed) 2025-11-05T12:00:19-05:00 (https://bsky.app/profile/did:plc:ipnqgjcngbafxdo3bv3gamrx/post/3m4vjl45f7x2n?refsrc=embed)
The Inevitable Inward Plunge
The process is straightforward yet brutal. As a star morphs into a red giant, planets in dangerously close proximity begin to fall inward due to overwhelming gravitational forces. Eventually, the star's immense bulk engulfs them entirely. Lead researcher Edward Bryant (https://embryant.github.io/) from the Mullard Space Science Laboratory at University College London and the University of Warwick explained (https://ras.ac.uk/news-and-press/research-highlights/ageing-stars-may-be-destroying-their-closest-planets):
'This provides solid proof that when stars leave the main sequence, they can rapidly draw planets toward them for destruction. This concept has been debated and modeled for years, but now we're witnessing its effects firsthand across a vast sample of stars.'
'We anticipated this phenomenon, yet we're astonished by how effectively these stars dismantle their nearby worlds.'
Scientists believe the devastation stems from a gravitational 'tug-of-war' known as tidal interactions. As the star expands and matures, these forces intensify.
Similar to how Earth's moon creates ocean tides by pulling on our planet, a planet exerts a pull on its star. These exchanges gradually decelerate the planet, shrinking its orbit until it disintegrates or plunges into the star.
For beginners, think of it like a cosmic game of catch where the star is a giant, growing hand that eventually traps and consumes the ball (the planet) through relentless pulling.
A Wealth of Planetary Data
The study encompassed 130 exoplanets and suspected planets—those flagged as possible but requiring verification—from TESS observations.
Starting with 15,000 potential signals, the team filtered out inaccuracies to arrive at these 130. Of them, 33 were fresh candidates unknown to science. Additionally, 48 were already confirmed planets, and 49 were prior candidates.
Scarcer Planets Around More Mature Red Giants
Remarkably, the findings showed that the older a star becomes—particularly in its advanced red giant phase—the fewer planets it retains. Stars that have evolved into red giants are considered post-main sequence, while those like our Sun are still on the main sequence (https://science.nasa.gov/universe/stars/types/#main-sequence).
Patterns also emerged within the post-main sequence category. Overall, planets appeared at a 0.28% rate. Newly formed red giants boasted a 0.35% occurrence, but this figure plummeted to 0.11% for more seasoned ones.
This bolsters the theory that as red giants age further and swell, they consume even more planets. Researchers are eager to probe deeper into how orbits begin to decay, which requires measuring planetary masses via TESS data. As Bryant added:
'With planetary masses in hand, we'll gain clearer insights into the mechanisms driving this spiraling doom.'
But here's where it gets controversial: Could some planets defy these odds and survive? Recent observations of puffy atmospheres on exoplanets near red giants suggest not all are doomed—raising debates about whether certain worlds might endure through unique adaptations or orbital dynamics. Is this a glimmer of hope, or just an exception proving the rule?
These discoveries also hint at our solar system's distant destiny. Our Sun will follow suit, and the question looms: Which planets might escape? Fortunately, that's billions of years away—plenty of time for humanity to ponder and perhaps even intervene.
And this is the part most people miss: If planets can be destroyed so efficiently, what does that say about the universe's capacity for habitability? Does it make life-bearing worlds rarer, or does it inspire us to cherish our own Earth more?
Wrapping it up: Astronomers have uncovered fresh proof that fading stars demolish their planets, with those in closest orbits facing the highest peril, as the stars metamorphose into red giants.
Source: Determining the impact of post-main-sequence stellar evolution on the transiting giant planet population (https://academic.oup.com/mnras/article/544/1/1186/8286899)
Via Royal Astronomical Society (https://ras.ac.uk/news-and-press/research-highlights/ageing-stars-may-be-destroying-their-closest-planets)
Read more: Phoenix exoplanet's puffy atmosphere survives red giant star (https://earthsky.org/space/exoplanets-puffy-atmosphere-phoenix-hot-neptune-exoplanets-red-giant-star/)
Read more: An all-sky red giant star symphony (https://earthsky.org/space/an-all-sky-red-giant-star-symphony/)
Paul Scott Anderson
View Articles (https://earthsky.org/author/paul-scott-anderson/)
About the Author:
Paul Scott Anderson's fascination with space began as a child mesmerized by Carl Sagan’s Cosmos. He pursued studies in English, writing, art, and computer/publication design through high school and college. In 2005, he launched his blog The Meridiani Journal, later rebranded as Planetaria, and followed with Fermi Paradoxica, exploring the quest for extraterrestrial life. Though captivated by all space facets, his heart lies in planetary science and SETI. Since 2011, he's freelanced for Universe Today, contributed to SpaceFlight Insider and AmericaSpace, appeared in The Mars Quarterly, and aided the Exoplanet app. EarthSky has been his writing home since 2018, where he also handles proofreading and social media.
What are your thoughts on this stellar cataclysm? Do you see this as a testament to the universe's harsh realities, or a call to protect our own planet? Could advanced technology one day save worlds from such fates? Share your opinions, agreements, or disagreements in the comments—let's discuss!
