Latest news with #ESPRESSO
Yahoo
31-03-2025
- Science
- Yahoo
This newly found super-Earth might have blown off its own atmosphere
When you buy through links on our articles, Future and its syndication partners may earn a commission. A super-Earth that could explain the universe's mysterious lack of certain exoplanets has been found by NASA's Transiting Exoplanet Survey Satellite (TESS) and the planet-measuring ESPRESSO instrument on the Very Large Telescope in Chile. "It's a small addition to the already long list of known planets, but such discoveries are essential to improve our understanding of the mechanisms of planet formation and evolution," said José Rodrigues of the Porto Institute of Astrophysics, who led the study, in a statement. "Many more [planets] will be needed to transform our hypotheses into scientific certainties." The exoplanet, named TOI-512b, is located 218 light-years away. It was first identified by TESS in 2020, which saw the planet transit, or regularly move in front of, its star, blocking some of the star's light from reaching our vantage point in the cosmos. Based on the amount of light blocked, astronomers measured TOI-512b's radius to be 1.54 times the size of Earth's. To confirm that TOI-512b is a real planet, and not a false-positive brought about by activity on the star, the ESPRESSO (Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observation) instrument on the Very Large Telescope measured the radial velocity of the world's star. This is the "wobble" in the star's rotation brought about by the gravity of the orbiting planet tugging on the star. ESPRESSO's measurements determined TOI-512b's mass to be 3.57 times that of Earth's. Knowing its radius and mass, astronomers could then calculate the average density of TOI-512b, determining it to have a bulk density of 5.62 grams per cubic centimeter. This is slightly denser than Earth, which has an average density of 5.52 grams per cubic centimeter. If TOI-512b were the size of Earth with this density, we would infer a solidly rocky planet — but TOI-512b is larger and more massive than Earth, and so the story is more complex. TOI-512b orbits its star every 7.1 days at a distance of just 9,863,797 kilometers (6,129,079 miles). This means that it gets rather hot — it's too close to its star to be in the habitable zone, receiving 112 times as much heat from its star as Earth does. Its size also places it just below what researchers call the "hot Neptune desert." Astronomers are finding exoplanets of myriad sizes and masses, but there seems to be a dramatic dearth of worlds between about 1.8 and 2.4 times the radius of Earth. This is the aforementioned desert, and one theory is that as Neptune-size worlds rich in gas and ice migrate inwards towards their star, stellar radiation blows their atmosphere away, removing much of the gas and leaving a smaller world at the end of the process. The other possibility is that it is leftover heat from a planet's formation that seeps out from its interior and into its thick gaseous layer, heating it so that it can escape more easily. This is referred to as core-powered mass loss. TOI-512b could have once been a Neptune-like world that lost most of its gas. Based on its density, mass and volume, Rodrigues' team modeled what the interior structure of the planet might be. They conclude that the best-fit model describes a small inner core making up 13% of the mass of the planet, a mantle contributing 69% and a water layer of up to 16% of the planet's mass, with the remaining 2% given over to the now-depleted gaseous layer. Compare that to Earth, where the mass-fraction of water is just 0.02%. Yet if TOI-152b had been reduced by stellar radiation, there would be no water or atmosphere left at all. Instead, Rodrigues' team suggest that the core-powered mass loss is the better explanation, particularly for TOI-152b's age of 8.235 billion years (albeit with an uncertainty of 4.386 billion years), since core-powered mass loss is a process that can last billions of years. That's not to say that all planets that pass through the hot Neptune desert lose their gaseous envelopes in this same way. It's possible that their gaseous layer can be removed by one or both of solar radiation and core-powered mass loss, depending upon the planet and the star. As Rodrigues stated at the beginning of this article, astronomers need many more examples before they can begin drawing solid conclusions. Related Stories: — Super-Earth orbits in and out of its star's habitable zone. Could life survive? — NASA space telescope finds Earth-size exoplanet that's 'not a bad place' to hunt for life — Massive new NASA exoplanet catalog unveils 126 extreme and exotic worlds The study also ruled out a second candidate planet that had been hinted at in the TESS observations. As for follow-ups, the planet might be a little too distant and difficult for the James Webb Space Telescope to perform transit spectroscopy — that is, studying a planet's atmosphere when that planet transits its star and some of the starlight is filtered through the atmosphere – with Rodrigues' team suggesting that this process with the JWST might be "tedious." Instead, they propose that the ANDES (Armazones high Dispersion Echelle Spectrograph) spectrometer on the forthcoming 39-meter (128 feet) Extremely Large Telescope at the European Southern Observatory in Chile might have better luck. The findings about TOI-512b were published on March 25 in Astronomy & Astrophysics.
Yahoo
17-03-2025
- Science
- Yahoo
Scientists Discover Four Intriguing Planets Around Closest Single-Star Solar System to Earth
Astronomers have spotted four smaller-than-Earth exoplanets orbiting the closest single-star system to us, called Barnard's Star. As detailed in a new paper published in the journal The Astrophysical Journal Letters, an international team of researchers discovered that the star — a small red dwarf star just 16 percent of our own Sun's mass and just under six light-years from Earth in the constellation Ophiuchus — has four tiny and seemingly rocky worlds orbiting it. According to the astronomers, these exoplanets — which are among the smallest ever discovered — could force us to reevaluate our understanding of how planets form and evolve. The four planets were spotted by the MAROON-X instrument, a highly sensitive piece of equipment attached to the Gemini North telescope at the International Gemini Observatory in Hilo, Hawaii. "It's a really exciting find — Barnard's Star is our cosmic neighbor, and yet we know so little about it," said University of Chicago PhD student and first author Ritvik Basant in a statement. "It's signaling a breakthrough with the precision of these new instruments from previous generations." MAROON-X was specifically designed to detect tiny exoplanets orbiting red dwarf stars by detecting the minuscule back-and-forth motion of a star caused by the gravitational pull of orbiting planets, a trick scientists call the radial velocity technique. Using the instrument, the team discovered four likely rocky exoplanets that are only anywhere from roughly 20 to 30 percent of the mass of Earth each. They orbit their star at an extremely close distance, completing a full revolution in a matter of a few Earth days. The team also used data from a 2024 study, which involved the ESPRESSO instrument at the European Southern Observatory's Very Large Telescope in Chile, to confirm the existence of one of the four exoplanets. Last year, astronomers detected an exoplanet with at least half the mass of Venus orbiting Barnard's Star. "We observed at different times of night on different days," said Basant in the statement. "They're in Chile; we're in Hawai'i. Our teams didn't coordinate with each other at all. That gives us a lot of assurance that these aren't phantoms in the data." One of the four exoplanets spotted by MAROON-X was the smallest to have been discovered using the radial velocity technique, which could set the stage for many future discoveries like it. Unfortunately, the planets are unlikely to harbor life since they're not in Barnard Star's habitable zone, the area around a star where temperatures allow liquid water to exist on a given planet's surface. "With the current dataset, we can confidently rule out any planets more massive than 40 to 60 percent of Earth's mass near the inner and outer edges of the habitable zone," Basant told "Additionally, we can exclude the presence of Earth-mass planets with orbital periods of up to a few years." But that doesn't necessarily mean that will also be the case for other single-star systems like it. As our exoplanet detection methods continue to improve, astronomers are hoping to spot even more rocky worlds, which may still turn out to be habitable. More on Barnard's Star: Astronomers Spot Mysterious Planet Orbiting the Closest Single Star
Yahoo
15-03-2025
- Science
- Yahoo
4 rocky exoplanets found around Barnard's Star, one of the sun's nearest neighbors
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have confirmed the existence of four small, rocky planets orbiting Barnard's Star — the second closest star system to Earth — using a specialized instrument on the mighty Gemini North telescope in Hawaii. Just six light-years away from us, all the worlds are too hot to support life as we know it. This find is particularly exciting, explained Ritvik Basant, who is a Ph.D. student at the University of Chicago and an author on a paper about the new discovery. This is because, he said, Barnard's Star is essentially our cosmic neighbor, yet we don't know very much about it. There have been many claims of exoplanets orbiting Barnard's Star over the years, dating all the way back to the 1960s. Barnard's Star is a red dwarf, also known as an M-dwarf, and is noticeable for having the fastest proper motion, in reference to its motion visible in the night sky, of any star so far discovered. Most recently, in 2024, astronomers using the ESPRESSO spectrograph on the Very Large Telescope in Chile claimed the detection of one planet, and evidence for a further three. Now, a team led by Jacob Bean and Basant at the University of Chicago has confirmed beyond a shadow of a doubt the existence of all four planets. "Barnard's Star's proximity allowed us to observe it even during bad weather nights, as its brightness made it accessible even under suboptimal conditions. This enabled us to collect more data, ultimately leading to the detection of these very low-mass planets," Basant told A key tool used in the team's observations was the MAROON-X spectrometer, which is a visiting instrument on Gemini North. MAROON-X measures the "radial velocity" — the slight wobble back and forth of Barnard's Star as it revolves around the center of mass shared between itself and the four orbiting planets. They're all much less massive than Earth. In fact, they are some of the least massive exoplanets ever detected. The innermost planet in the system is planet d (the planets are named in order of discovery, not distance from the star), which has a mass just 26% that of Earth's and orbits Barnard's Star every 2.34 days at a distance of 1.7 million miles (2.8 million kilometers/0.0188 astronomical units). Next up is planet b: the planet first identified in the ESPRESSO data in 2024. This planet has a mass 30% that of Earth's, and orbits its star every 3.15 days at a distance of 2.13 million miles (3.4 million kilometers/0.0229 AU). Planet c is the heavyweight of the bunch, with a mass 33.5% that of Earth's. It orbits Barnard's Star at a distance of 2.55 million miles (4.1 million kilometers/0.0274 AU) and has an orbital period of 4.12 days. The first three planets were confirmed using just the MAROON-X observations. To confirm the fourth planet, e, the MAROON-X data had to be combined with ESPRESSO's measurements to reveal a planet with just 19% of Earth's mass, orbiting Barnard's Star every 6.74 days at a distance of 3.56 million miles (5.7 million kilometers/0.0381 AU). These worlds are incredibly compact in terms of distance to one another, with just 372,820 miles (600,000 kilometers) between planets d and b, and 434,960 miles (700,000 kilometers) between b and c. For comparison, the mean distance between Earth and our moon is just 238,600 miles (384,000 kilometers). Imagine having a planet on our doorstep at just twice that distance! Yet, that is how things are arranged around Barnard's Star. For an even starker contrast, NASA's Parker Solar Probe, which actually dives into the solar corona, gets as close as 3.9 million miles (6.2 million kilometers) to the surface of our sun. The orbits of all four planets around Barnard's Star could easily fit inside Parker's Solar Probe's orbit. And, to further the contrast between our solar system and Barnard's Star's planetary system, the closest planet to the sun in our Solar System, Mercury, has a mean distance of 36 million miles (58 million kilometers) between itself and the sun. The small separations between the planets around Barnard's Star also bring to mind another system of worlds around a red dwarf, TRAPPIST-1, where seven planets are packed within 5.75 million miles (9.267 million kilometers) of their central star. A red dwarf like Barnard's Star is very different to our sun, however. It has just 16% of our sun's mass, and 19% its diameter. As such, its planetary system is scaled down. Red dwarfs can also be very volatile, spewing clouds of charged particles and flares of radiation more frequently than our sun does, which could strip nearby worlds of their atmospheres. However, red dwarf activity does decrease with age, and the Barnard's Star system is about 10 billion years old. That said, none of the planets found so far would be habitable to life as we know it anyway, since they are too close and too hot. Instead, the habitable zone around Barnard's Star would coincide with worlds farther out, with orbital periods of between 10 and 42 days. So far, no planets have been found that far out from the star. "With the current dataset, we can confidently rule out any planets more massive than 40 to 60% of Earth's mass near the inner and outer edges of the habitable zone," sBasant said.. "Additionally, we can exclude the presence of Earth-mass planets with orbital periods of up to a few years. We are also confident that the system does not host a gas giant within reasonable distances." MAROON-X was able to gather 112 radial velocity measurements of Barnard's Star throughout the period 2021–2023. Meanwhile, ESPRESSO has recorded 149 radial velocity measurements of the fleet-footed but diminutive star. This isn't enough to completely rule out the possibility of any more small planets that might be lurking in the habitable zone. "We also have additional data from 2024 that was not used in this discovery," said Basant. "If I had to choose a number, I would estimate that 50 more data points would be ideal for achieving the best sensitivity possible with current instruments." MAROON-X is specifically designed for measuring radial velocities of red dwarf systems. The focus on red dwarfs is two-fold. One reason is that they are the most populous type of star in the galaxy and make up the majority of the closest stars to us. Second, their small masses make it easier to detect wobbles in their movements caused by Earth-size rocky planets. Placed on an eight-meter class telescope such as Gemini North, and able to view into the near-infrared where red dwarfs such as Barnard's Star are brighter, MAROON-X is perfectly placed to seek these scaled-down planetary systems. "This discovery was possible due to a combination of factors," said Basant. "If I had to choose one, it would be the unprecedented precision of next-generation instruments like MAROON-X and ESPRESSO." Unfortunately, the four planets of Barnard's Star do not transit, or pass in front of their star, from our point of view. This means that we cannot observe secondary eclipses (where the planets move behind their star, allowing us to subtract the star's light from the combined light of the star and planets, to be left with just the light of the planets) or transit spectroscopy (where starlight is filtered through planetary atmospheres, if they have one, revealing molecules that may be present). — Does exoplanet K2-18b host alien life or not? Here's why the debate continues — Temperamental stars could be ruining our view of thousands of exoplanets, Hubble Telescope finds — Strange multi-planet system proves not all hot Jupiter exoplanets are lonely giants However, "hile these planets do not transit, their thermal emission can be studied with [the James Webb Space Telescope], though this remains challenging," says Basant. In the meantime, Basant, Bean and their team intend to keep looking for more planets orbiting Barnard's Star. After all, we're practically neighbors — and it's about time that we found and got to know this planetary system next door. The findings were published on March 11 in The Astrophysical Journal Letters.
Yahoo
24-02-2025
- Science
- Yahoo
This exoplanet has weather never before seen in the universe
Scientists say they are rethinking how the weather works after creating a 3D map of an exoplanet 900 light-years away and discovering a world with jet streams fueling wild storms. WASP-121b, nicknamed Tylos, is a gas giant with a few things in common with Jupiter, but there are more differences than similarities between these two worlds. Researchers used all four telescopes at the European Southern Observatory (ESO) in Chile to study the climate and weather patterns on Tylos. According to the ESO, this is the first study in such detail of a world outside our solar system. "This planet's atmosphere behaves in ways that challenge our understanding of how weather works – not just on Earth, but on all planets. It feels like something out of science fiction," ESO researcher Julia Victoria Seidel said. Astronomers Discover Largest Superstructure In Cosmos Tylos rotates counterclockwise so that one side always faces its system's star. This causes one side of the planet to be scorching hot and always daytime. The opposite side is cool and always night. Because of its closeness to the star, a year on Tylos only lasts about 30 hours. Using the ESO's ESPRESSO instrument to combine the light of the four large telescope units into a single signal, the science team was able to detect signatures of multiple chemicals making up layers in Tylos' atmosphere. The team found that the atmosphere on Tylos has layers, each with a unique chemical makeup, including iron, sodium and hydrogen. The graphic below shows the layers: the deepest layer of the atmosphere contains iron, followed by a fast jet stream of sodium moving faster than the planet's rotation, which accelerates as it moves from the hot to the cool side. Lastly, the upper layer of the atmosphere contains hydrogen blasting out from the planet and overlapping with the sodium jet beneath. "What we found was surprising: a jet stream rotates material around the planet's equator, while a separate flow at lower levels of the atmosphere moves gas from the hot side to the cooler side. This kind of climate has never been seen before on any planet," Seidel said. How To Watch Fox Weather These observations showed jet streams spanning half the planet, churning storms high in the sky as they scream across the hot side of the planet. These storms would rival Jupiter's Great Red Spot, the largest storm in our solar system. "Even the strongest hurricanes in the solar system seem calm in comparison," Seidel said. Astronomers will soon be able to study weather on smaller Earth-sized worlds with ESO's Extremely Large Telescope (ELT), currently under construction in Chile's Atacama article source: This exoplanet has weather never before seen in the universe
Yahoo
18-02-2025
- Science
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Exoplanet with iron rain has violent winds 'like something out of science fiction'
When you buy through links on our articles, Future and its syndication partners may earn a commission. WASP-121 b is the definition of an "extreme" exoplanet — it's so hot that it rains droplets of liquid iron. Now, astronomers have discovered that this planet, located around 900 light-years away from us, is also ravaged by unexpectedly powerful represents the first time astronomers have been able to study the atmosphere of a planet outside the solar system in such intricate depth and WASP-121 b winds, discovered by a team of astronomers using the Very Large Telescope (VLT) located in the Atacama Desert region of northern Chile, carry elements like iron and titanium around the planet, therefore creating intricate weather patterns. "This planet's atmosphere behaves in ways that challenge our understanding of how weather works — not just on Earth, but on all planets," team leader and Observatoire de la Côte d'Azur researcher Julia Victoria Seidel said in a statement. "It feels like something out of science fiction." Many of the extraordinary features of WASP-121 b arise from the fact that it is an ultra-hot Jupiter, a gas giant planet with around 1.2 times the mass of its solar system namesake. WASP-121 b actually orbits so close to its star that a year there lasts just 30 Earth proximity also means that WASP-121 b is "tidally locked," meaning one side of the world permanently faces its star (its scorching hot dayside) while the other (the nightside) is cooler because it faces out to space in perpetuity. Iron and other metals are vaporized on the scorching hot dayside and are blown across the planet to its nightside, where they condense and fall as liquid metal rains. Delving deep into the atmosphere of WASP-121 b and creating a 3D map of its atmosphere, researchers found different kinds of winds in different layers of the world; they also observed a jet stream spanning half of the planet. As this jet stream gains speed, it appears to violently churn WASP-121 b's atmosphere high up in the sky as it crosses the line between the planet's nightside and dayside, moving toward the hotter half. "What we found was surprising: a jet stream rotates material around the planet's equator, while a separate flow at lower levels of the atmosphere moves gas from the hot side to the cooler side," Seidel said. "This kind of climate has never been seen before on any planet. "Even the strongest hurricanes in the solar system seem calm in comparison." This complex mapping of WASP-121 b's atmosphere was possible thanks to the VLT instrument ESPRESSO (Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations). The VLT combines light from different telescopes; it analyzes four times as much light as is available to a single instrument, and this allows it to obtain much fainter details of a planet's atmosphere. The team trained ESPRESSO on WASP-121 b for one full passage in front of its star's face, or one full "transit." This let the researchers detect the signature of multiple chemicals in the atmosphere of the ultra-hot Jupiter across different atmospheric layers. "The VLT enabled us to probe three different layers of the exoplanet's atmosphere in one fell swoop," Leonardo A. dos Santos, team member and a researcher at the Space Telescope Science Institute, said in the statement. Related Stories: — 'Roasting marshmallow' exoplanet is so hot, it rains metal. How did it form? — Extreme 'hot Jupiter' exoplanet stinks like rotten eggs and has raging glass storms — Iron winds and molten metal rains ravage a hellish hot Jupiter exoplanet The researchers tracked the movement of iron, sodium and hydrogen, using these elements to track winds in the deep, middle and shallow layers of WASP-121 b's atmosphere. "It's the kind of observation that is very challenging to do with space telescopes, highlighting the importance of ground-based observations of exoplanets," dos Santos said. One surprise this investigation delivered was the discovery of titanium lurking just below the jet stream. Previous observations of WASP-121 b have shown this element to be absent. The discrepancy could be because the titanium content was hidden deep in the ultra-hot Jupiter's atmosphere. "It's truly mind-blowing that we're able to study details like the chemical makeup and weather patterns of a planet at such a vast distance," Bibiana Prinoth, a researcher at Lund University researcher and author of a companion paper detailing the titanium discovery, said in the statement. The team's research was published on Tuesday (Feb. 18) in the journal Nature.
