Planets with two suns have intrigued our cosmic imagination since they appeared in a popular work of fiction set in a galaxy far, far away. That’s right, the world-famous King in Yellow, published in 1895. Oh, and Star Wars, of course. But can potentially habitable planets really exist in binary star systems? New research suggests yes, absolutely, and for a long time, while crushing hopes for giant planets in the system behind the oldest exoplanet claim ever proposed. An illustration of a Saturn-style planet orbiting the main star in a binary system. (NASA/ESA/CSA/STScI/Robert Hurt/Caltech/IPAC) Our Solar System is unusual because it is the only one we know of with robots moving between its planets. But also for astrophysical reasons: “Our solar system, with a single star, is somewhat unusual. Many stars have stellar companions,” explains Stephen Kane, an astrophysicist at the University of California at Riverside (UCR) and one of the co-authors of the study. “You might imagine that second star showing up like a wrecking ball and making it impossible for an Earth-sized planet to survive in the habitable zone. But these simulations show that’s not necessarily the case.” frameborder=”0″ enable=”accelerometer; autoplay; writing on clipboard; encrypted media; gyroscope; picture in picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” enablefullscreen> A huge astronomy team from more than a dozen institutions focused on the binary system called 70 Ophiuchi (70 Oph AB), whose two stars are K dwarfs that have about 88 percent and 73 percent the mass of the Sun and are possibly about 3 billion years old, according to the team’s calculations. The orange K dwarfs are a 70 Oph AB is particularly attractive because it is in our stellar neighborhood, just 16 light-years away, or four times farther away than our closest neighbors in Proxima. The Centauri system has also been known as a binary for almost 250 years, thanks to William Herschel. An image of 70 Oph AB, taken by the US Naval Observatory (US Naval Observatory). Thus, the team incorporated recent and archival radial velocity (RV) measurements of both stars, including data from eight instruments for the primary star, over a century of observing. RV is the second most successful method of planet searching in our arsenal. astrophysicist, responsible for more than 250 years. from the local donut shop. That astronomers could measure this change in the speed of an entire star, a giant nuclear furnace billions of kilometers away, is a testament to science. The researchers then injected signals from fake planets into their trove of data to see what they could detect Earth-mass planets at 2,000 different distances from the primary star, tracking each one for 10 million years. the limits of the habitable zone around the primary star. “I then tested whether an Earth-mass planet could maintain a stable orbit at different distances within that zone,” explains Skylar D’Angiolillo, a researcher in Earth and planetary sciences at UCR and one of the co-authors of the study. “What we discovered is that stable orbits are possible in the habitable zone of the primary star. You might expect the second star to disrupt those orbits, but that’s not necessarily what happens. “The probabilities of planetary survival in the researchers’ simulations, depending on distance. (Li et al., ApJ, 2026) The researchers were also able to rule out the presence of giant exoplanets with the mass of Jupiter or larger around the two stars, about five astronomical units (AU) from the main star, or about the distance from the Sun at which a gas giant with the mass of Jupiter exists. in our own Solar System (hint: Jupiter). This is intriguing because in 1855, British astronomer William Jacob claimed that 70 Oph AB had a planet, making it the first host of an exoplanet candidate, researchers at the University of Michigan (UM) note. Jacob’s claim did not survive scrutiny, but more recent measurements showed a “wobble” that could still have been explained by a planet the size of Jupiter. “It’s a mix of disappointment and excitement,” says Yiting Li. UM astronomer and first author of the study. “We are discovering that a planet the size of Jupiter does not exist, but we are also opening the last chapter on this historical system.” “All stars in the sky have one or more partners,” so this can significantly expand our future exploration efforts, especially when next (next) generation observations come online, such as NASA’s promising Habitable Worlds Observatory (HWO), designed to specifically explore and directly image alien worlds. “Overall, our results demonstrate that the 70 Oph system is likely to host planets in S-type orbits around the primary star, including terrestrial planets in stable orbits within the primary star. [habitable zone] region,” the researchers conclude. “If stellar binaries can host Earth-like planets, 70 Oph is one of the best places to look.” The research has been published in The Astrophysical Journal. This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. 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