Latest news with #Triaud
Yahoo
04-05-2025
- Science
- Yahoo
What would it be like living on Tatooine from 'Star Wars'? This exoplanet orbiting twin suns could tell us
When you buy through links on our articles, Future and its syndication partners may earn a commission. A Tatooine-like world with a key difference from the desert planet in "Star Wars" has been serendipitously discovered orbiting not two stars, but a pair of brown dwarfs. What's more, this wacky planet doesn't orbit around the brown dwarfs' equator, but instead up and down over their poles. In the "Star Wars" universe, Luke Skywalker famously came from the planet of Tatooine, which had two suns and double sunsets. Tatooine is in a circumbinary orbit, which means that it doesn't orbit one star, but instead orbits both stars of a binary system. Binary systems are common in our Milky Way galaxy — about two-thirds of all stars (and brown dwarfs) are found in binary systems. Yet given the near ubiquity of these stellar pairs, very few planets have been discovered on circumbinary orbits — just 16 up until now. Those 16 all orbit around the equatorial plane of their double star system — such orbits are said to be 'co-planar'. This is just one of the reasons that this new Tatooine-like planet, which is 118 light years away and called 2M1510(AB)b, is rather unique. Another reason is that it orbits two brown dwarfs (which also happen to eclipse each other from our point of view, and are only the second pair of eclipsing brown dwarfs to have been found). Brown dwarfs are sometimes referred to as 'failed stars' — they are objects that form like a star by collapsing directly out of a molecular gas cloud, but which are not massive enough to generate the temperatures and pressures required at their core for hydrogen-based fusion reactions. The concept of planets on polar orbits isn't entirely surprising. Previous studies have discovered planets on polar orbits around single stars, while the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile has observed dusty protoplanetary disks tilted around young binary stars. However, 2M1510(AB)b is the first bonafide planet to be found on a circumbinary polar orbit. "Our expectation is that the planet would have formed in an inclined disc, such as those observed by ALMA," said Amaury Triaud, a professor of astronomy at the University of Birmingham, UK, in an interview with Triaud was part of the research team that discovered this planet. There are, however, some caveats. One is the planet's distance from the brown dwarfs, which at this current time is unknown. If it is too far away, then the disk from which it formed would have been harder to tilt. In this case, alternative ideas would have to be considered, such as an interaction with a passing star. We don't know the orbital period of 2M1510(AB)b, nor its diameter and mass, because this planet wasn't discovered in a conventional way. Triaud is part of a team led by Thomas Baycroft, who is a PhD student at Birmingham. They were targeting the brown dwarfs with the Very Large Telescope in Chile, with the aim of constraining the two brown dwarf's orbital parameters around each other. But they began to notice the very subtle effect of the brown dwarfs being tugged this way and that by an unseen body. Putting their data into various models, they found that the best explanation is that of a large planet, between 10 and 100 times the mass of Earth, on a polar orbit aligned 90 degrees to the equatorial plane of the brown dwarfs. Intriguingly, a circumbinary polar orbit is more stable than a co-planar orbit, says Triaud. This is not necessarily the case for planets on polar orbits around single stars. "We still do not fully understand why certain planets orbiting single stars are on polar orbits, and since what we've found is the first polar circumbinary geometry, we also do not know much about it," he said. "For single stars, the planetary orbit could have misaligned, or the stellar rotation axis could have moved. A final scenario, which I am very skeptical about, is that polar planets orbiting single stars were once circumbinary planets themselves, with the two stars coalescing." Audiences have been wowed over the years by Tatooine's double sunset in Star Wars, and planets in circumbinary orbits do have different diurnal and seasonal patterns compared to Earth. On a circumbinary planet, the length of day would depend upon how far apart the stars are in the sky at any one time. At their widest angular separation, the days would last longer than when the stars are close together in the sky. Also think about their orbits. The two stars are orbiting the center of mass between them, and a circumbinary planet orbits both stars as they move about this center of mass. As the planet orbits around them, it will at different times find itself closer to one star than the other, and at other times be equidistant to both stars. This dance of stars and planet would undoubtedly have an effect on the planet's climate. "A circumbinary planet experiences a sort of seasonal modulation, on roughly the timescale of the binary orbit, or half of it," said Triaud. There's lots of potential permutations here. If both stars are of similar mass, then the planet will experience winter when it is closer to just one of them, and summer when they are equidistant. If they have different masses, say a sun-like star and a cool, feeble red dwarf, then the warmer seasons would occur when a circumbinary planet is closer to the more massive star. It's even plausible that a planet could dip in and out of the habitable zone — it would be inside the habitable zone when it's closer to the more massive star, and out when it is nearer the smaller, cooler star. But how would a circumbinary planet on a polar orbit fare? "A polar planet would also feel a little like this since the stars constantly move and change distance relative to the planet, but the effect would be reduced compared to a co-planar situation," said Triaud. RELATED STORIES: — New Tatooine-like exoplanet discovered orbiting twin suns. Meet BEBOP-1c. — How common are Tatooine worlds? — Astronomers discover doomed planet shedding a Mount Everest's worth of material every orbit, leaving behind a comet-like tail The 2M1510 system also has a third brown dwarf farther out that the planet does not orbit. It is unlikely that there would be life on 2M1510(AB)b — brown dwarfs are far too cool to keep a planet warm enough for liquid water. Luke Skywalker's homeworld of Tatooine is a dry desert world, with very subtle seasons. During the double sunset, we see two sun-like stars close together. Perhaps they are on a tight orbit around one another, meaning their distance from the planet stays fairly similar. Luke found life on Tatooine to be boring, but he should be glad, because as we have seen, binary stars have the potential to play all kinds of havoc on their orbiting circumbinary planets. The discovery of this first-ever circumbinary polar planet was published on April 16 in Science Advances.
Daily Record
22-04-2025
- Science
- Daily Record
Scientists discover first 'polar planet' orbiting two stars in ‘surprise' find
The planet orbits two stars at once, like the fictional Star Wars world Tatooine. Astronomers have found a planet that orbits around a rare pair of peculiar stars in what has been dubbed a "surprising" discovery. This discovery is the first strong evidence of a 'polar planet' orbiting a pair of stars. Scientists used the European Southern Observatory's Very Large Telescope (VLT) to make this exciting discovery. Several planets orbiting two stars at once have been discovered in the past years, but none that orbited their stars in this interesting way had been found. Star Wars fans may recognise that phenomenon from the fictional planet Tatooine in the film franchise. And Science Daily explains that these odd planets typically occupy orbits that roughly align with the angle in which their host stars orbit each other. However, this particular 'polar planet' orbits at a 90 degree angle around its stars. Previous theories assumed that these orbits would be stable, and hints of these planets existing had been found, but there was a lack of clear evidence that these polar planets existed until now. Thomas Baycroft, a PhD student at the University of Birmingham, who led the study published in Science Advances, said: "I am particularly excited to be involved in detecting credible evidence that this configuration exists." The exoplanet, named 2M1510 (AB) b, orbits a pair of young brown dwarf stars, which are bigger than gas-giant planets but too small to be considered proper stars. The two brown dwarfs produce eclipses of one another as seen from Earth, in a phenomenon that astronomers call an 'eclipsing binary'. This star system is incredibly rare, and it is only the second pair of eclipsing brown dwarfs known to date. The system also contains the first exoplanet ever found on a path at right angles to the orbit of its two host stars. "A planet orbiting not just a binary, but a binary brown dwarf, as well as being on a polar orbit is rather incredible and exciting," says co-author Amaury Triaud, a professor at the University of Birmingham. The planet was found while the team was refining the orbital and physical parameters of the two brown dwarfs - but it wasn't a discovery they were expecting. Triaud added: "The discovery was serendipitous, in the sense that our observations were not collected to seek such a planet, or orbital configuration. As such, it is a big surprise." Scientists collected observations with the Ultraviolet and Visual Echelle Spectrograph (UVES) instrument on ESO's Very Large Telescope at Paranal Observatory, Chile. This pair of brown dwarfs, known as 2M1510, were first detected in 2018 by the research's co-author Triaud. The astronomers noticed that the orbital path of the two stars in 2M1510 were being pushed and pulled in unusual ways, which led to the discovery of this exoplanet with its strange orbital angle. Baycroft explained that it became clear that the only explanation for this push-pull effect was that there was a planet orbiting at a 90 degree angle to the stars. "Overall, I think this shows to us astronomers, but also to the public at large, what is possible in the fascinating Universe we inhabit", says Triaud. Join the Daily Record WhatsApp community! Get the latest news sent straight to your messages by joining our WhatsApp community today. You'll receive daily updates on breaking news as well as the top headlines across Scotland. No one will be able to see who is signed up and no one can send messages except the Daily Record team. All you have to do is click here if you're on mobile, select 'Join Community' and you're in! If you're on a desktop, simply scan the QR code above with your phone and click 'Join Community'. We also treat our community members to special offers, promotions, and adverts from us and our partners. If you don't like our community, you can check out any time you like. To leave our community click on the name at the top of your screen and choose 'exit group'.
