Your support = more science, more stars, more wonder.<\/strong> Do old stars destroy the planets closest to them? Scientists have long known that stars like the sun eventually expand into red giants as they begin to die. It\u2019s been assumed that any exoplanets close enough to the original star would be consumed. On November 5, 2025, researchers at University College London and the University of Warwick in the U.K. presented more evidence to show that\u2019s the case. They studied nearly half a million red giant stars. And they determined that exoplanets were much less likely to be found around the red giants, especially older red giants, than around other stars. This suggests that many planets \u2013 the closest ones in particular \u2013 might have already been destroyed.<\/p>\n Using data from NASA\u2019s Transiting Exoplanet Survey Satellite (TESS), the researchers identified 130 planets and planetary candidates. Of those, 33 were new and previously unknown.<\/p>\n The researchers published their peer-reviewed findings in Monthly Notices of the Royal Astronomical Society<\/em> on October 15, 2025.<\/p>\n Observations indicate that giant planets orbiting close to aging stars are less common around red giants, suggesting many may be destroyed as their host stars expand and evolve.<\/p>\n \u2014 Science X \/ Phys.org (@sciencex.bsky.social) 2025-11-05T12:00:19-05:00<\/p>\n<\/blockquote>\n The scenario is fairly simple. As the star swells into a red giant, planets that are too close will start to spiral inward due to the powerful gravitational pull. Ultimately, the bloated giant star consumes them. Lead author Edward Bryant at Mullard Space Science Laboratory at University College London and the University of Warwick in the U.K. explained:<\/p>\n This is strong evidence that as stars evolve off their main sequence, they can quickly cause planets to spiral into them and be destroyed. This has been the subject of debate and theory for some time, but now we can see the impact of this directly and measure it at the level of a large population of stars.<\/p>\n We expected to see this effect, but we were still surprised by just how efficient these stars seem to be at engulfing their close planets.<\/p>\n We think the destruction happens because of the gravitational tug-of-war between the planet and the star, called tidal interaction. As the star evolves and expands, this interaction becomes stronger.<\/p>\n Just like the moon pulls on Earth\u2019s oceans to create tides, the planet pulls on the star. These interactions slow the planet down and cause its orbit to shrink, making it spiral inward until it either breaks apart or falls into the star.<\/p>\n<\/blockquote>\n Overall, the research team studied 130 exoplanets and planetary candidates (planets that are tentatively identified but need to be confirmed) in the TESS data.<\/p>\n Initially, the researchers started with 15,000 possible planetary signals. Then, after eliminating false positives, they reduced the number to 130. And 33 of those were brand-new candidates not known before. In addition, astronomers already knew of 48 of the planets, and 49 that scientists had already identified as planetary candidates.<\/p>\n Notably, the researchers found that the older the star \u2013 in the late red giant stage \u2013 the fewer planets it had. Stars that have aged enough to become red giants are post-main sequence stars<\/em>. Stars that haven\u2019t reached that stage yet, like our own sun, are main sequence stars.<\/p>\n Likewise, there was also a noticeable pattern with the age of the stars within the post-main sequence stage. The overall occurrence rate of planets was 0.28%. The \u201cyoungest\u201d ones \u2013 stars that had just become red giants \u2013 had planets at a rate 0f 0.35%. But, as the red giant stars themselves continued to get older, that rate dropped to 0.11%.<\/p>\n This supports the scenario that as red giants continue to age and expand, they engulf more of their planets. The researchers still want to understand better just how<\/em> the planets begin to spiral inward to their stars. To do so, astronomers need to know their masses, which they can find using the TESS data. As Bryant noted:<\/p>\n Once we have these planets\u2019 masses, that will help us understand exactly what is causing these planets to spiral in and be destroyed.<\/p>\n<\/blockquote>\n The findings also foreshadow the fate of our own solar system. Indeed, our own sun faces the same fate. Will any of the planets survive? Luckily for us, it\u2019s still several billion years in the future!<\/p>\n Bottom line: Astronomers have found new evidence that dying stars destroy their planets \u2013 with the closest planets at greatest risk \u2013 as the stars swell up into red giants.<\/p>\n Source: Determining the impact of post-main-sequence stellar evolution on the transiting giant planet population<\/p>\n Via Royal Astronomical Society<\/p>\n Read more: Phoenix exoplanet\u2019s puffy atmosphere survives red giant star<\/p>\n Read more: An all-sky red giant star symphony<\/p>\n <\/div>\n
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Old stars destroy their planets<\/h3>\n
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Spiraling to destruction<\/h3>\n
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130 planets and planetary candidates<\/h3>\n
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Fewer planets for older red giant stars<\/h3>\n
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