Latest news with #Sun-like
Yahoo
2 days ago
- General
- Yahoo
Scientists Startled by Discovery of Small Star Swimming Through Outer Layers of Another Larger Star
A team of researchers in China have discovered a stunning binary system in which a stellar object known as a pulsar orbited inside the outer layers of its companion star — which it accomplished after stripping its host's innards and dispersing them into space. The findings, detailed in a new study published in the journal Science, are an incredibly rare example of a "spider star" that preys on its companion, so-named because of the female arachnids that devour males after mating. And tantalizingly, the grisly scene is some of the best evidence yet of a stage of stellar evolution called the common envelope phase, which has never been directly observed by astronomers. Pulsars are rapidly spinning neutron stars, the incredibly dense stellar cores that are left over in the aftermath of a supernova. Everything about neutron stars exhaust superlatives — their gravity most of all. They are so tightly packed, containing more mass than our Sun inside a form just a dozen miles in radius, that all their atoms and their constituent protons and electrons have been crushed into neutrons, with just a teaspoon of this improbable matter weighing trillions of pounds. Their powerful magnetic fields, billions of times stronger than Earth's, unleash beams of radio waves into space along their poles. Further beggaring belief, some neutron stars become pulsars, which spin up to hundreds of times per second after siphoning material from a stellar companion, if it has one. Their sweeping beams of radiation, like cosmic lighthouses, look like a repeating signal to observers. The newly discovered pulsar, PSR J1928+1815, intrigued the astronomers because its radio pulses suggested that it was extremely close to its host, completing an orbit every 3.6 hours. They also noticed that for one-sixth of that orbit, the pulsar would vanish from view, indicating that the host was eclipsing it. "That's a large part of the orbit," coauthor Jin-Lin Han, a radio astronomer at the National Astronomical Observatories in Beijing, told Gizmodo. "That's strange, only a larger companion can do this." Over four and a half years, Han's team closely observed the system using the Five-hundred-meter Aperture Spherical Radio Telescope (FAST) in southern China, the largest and most powerful single-dish radio telescope in the world. Their observations revealed that the host star was between one to 1.6 times the mass of our Sun, while the pulsar was more likely 1.4 stellar masses. Determining the make of the host star, however, took some additional sleuthing. Its tight orbit and the fact that it was only detectable in radio wavelengths, Giz noted, ruled out its being a Sun-like star. And since it was large enough to eclipse the pulsar, it had to be something larger than a stellar remnant like another neutron star. That pointed to something altogether more spectacular: a helium star, created after the pulsar, when it was still an ordinary neutron star, tore off its host's layers and created a huge common envelope, a cloud of hydrogen gas that swallows both the stars. In this case, the poor star under attack managed to cling on to its evacuated innards for just 1,000 years — a blink in a stellar lifespan — before the whole, mighty envelope fell apart. Fleeting as it was, its impact is lasting: the friction exerted by the gases gradually nudged both stars closer together. Common envelopes are rare because the process of a neutron star stripping its companion, which causes it to spin and graduate to a pulsar, usually results in all the siphoned material being devoured. But if the companion is massive enough, much of it survives. The discovery marks the first spider star found orbiting a helium star. While the astronomers didn't get to witness the envelope in action, this is some of the most convincing evidence to date that this long-theorized stage of stellar evolution exists. In all, the team estimates that there're just 16 to 84 star systems like this one in the entire Milky Way — and, against all odds, we got to see one. More on space: Scientists Puzzled by Mysterious Motion in Atmosphere of Saturn's Moon
NDTV
17-05-2025
- Science
- NDTV
NASA's James Webb Telescope Spots Frozen Water In Distant Star System For The First Time
Using NASA's James Webb Space Telescope (JWST), a team of astronomers has confirmed the presence of frozen water in a distant but young star system. While scientists have found plenty of water ice in our solar system, it is the first time that they have definitive proof of frozen water in other star systems. The details, published in the journal Nature, state that crystalline water ice has been found in a dusty debris disk that orbits a Sun-like star, only 23 million years old, 155 light-years away. The star is slightly more massive and hotter than the Sun, which led to the formation of a slightly larger system around it. Webb's findings showed there is a significant gap between the star, named HD 181327, and its debris disk, which is similar to our solar system's Kuiper Belt. "Webb unambiguously detected not just water ice, but crystalline water ice, which is also found in locations like Saturn's rings and icy bodies in our solar system's Kuiper Belt," said Chen Xie, the lead author of the new paper. "HD 181327 is a very active system. There are regular, ongoing collisions in its debris disk. When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect." Implication The presence of water ice in a similar region could point towards a pattern about how planetary systems evolve across the universe. It may be more than a coincidence that the first confirmed water ice we're seeing around another star mirrors the distribution of our solar system. Additionally, the water ice is not spread evenly throughout this system, with the majority of it found where it's coldest and farthest from the star. "Toward the middle of the debris disk, Webb detected about eight per cent water ice. Here, it's likely that frozen water particles are produced slightly faster than they are destroyed." Scientists have long posited that ice could be present in debris disks, but prior to Webb, they did not have the instruments sensitive enough to make such observations. After the success with HD 181327, the researchers are expected to increase their efforts to search for and study water ice in debris disks in actively forming planetary systems throughout the Milky Way galaxy.
Yahoo
16-05-2025
- Science
- Yahoo
NASA's James Webb Telescope Just Found Frozen Water Around Another Star
Water ice is a crucial building block of planetary systems. We've found plenty of it in our own Solar System, in places like Europa, Mars, and wayward comets, but we've never made a definitive detection of frozen water around other stars. Plenty of water vapor, yes, but no (d)ice. But that just changed. Using NASA's James Webb Space Telescope, a team of astronomers have confirmed the presence of water ice in a debris disk encircling a young, Sun-like star just 155 light years away. And tantalizingly, it's the same kind of ice found in our own system. "Webb unambiguously detected not just water ice, but crystalline water ice, which is also found in locations like Saturn's rings and icy bodies in our Solar System's Kuiper Belt," said Chen Xie, an assistant research scientist at Johns Hopkins University and lead author of a new study published in the journal Nature, in a statement about the work. We tend to think of water in biological terms — as a key ingredient for life. But frozen chunks of the stuff play just as influential a role in the formation of giant planets, which, with their incredible mass, are themselves a huge determinant of a planetary system's structure. Icy bodies can clump together to kickstart planetary formation, and they could also bring water to existing worlds. In fact, that could explain how Earth got its water. The findings, therefore, have paved the way to exploring water ice's role outside our solar system. "The presence of water ice helps facilitate planet formation," Xie said. "Icy materials may also ultimately be 'delivered' to terrestrial planets that may form over a couple hundred million years in systems like this." The star at the heart of the discovery, HD 181327, is practically an infant at just 23 million years old, compared to the Sun's 4.6 billion years. It is both slightly more massive than our star, and hotter, with a larger system surrounding it. There's a vast stretch of empty space between the star and its debris disk where the water ice was found, Webb observations confirmed. Like "dirty snowballs," the ice chunks are caked in particles of dust. "There are regular, ongoing collisions in its debris disk," explained coauthor Christine Chen, an associate astronomer at the Space Telescope Science Institute in Baltimore, in the statement. "When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect." Most of the water ice is found farther away from the star, with the debris disk's outer area consisting of over 20 percent water ice, Xie said. Meanwhile, in the middle of the disk, Webb only detected 8 percent water ice, where water particles are likely produced slightly faster than they're vaporized. But in the region nearest the star, there was almost none to be found. There, the astronomers believe that the star's ultraviolet light vaporizes the ice chunks, and if any survive, they might be hidden from Webb's eye, trapped inside chunks of rock called planetesimals, which serve as the building blocks of planets. Strikingly, the debris disk appears remarkably similar to our Solar System's Kuiper Belt, a ring of comets, dwarf planets, and icy objects that lie just beyond the outermost planet, Neptune. That could hint at a pattern in how planetary systems evolve across the cosmos. It may be more than a coincidence that the first confirmed water ice we're seeing around another star mirrors the distribution of our Solar System. Only future observations — and probably with the James Webb — will tell. More on space: Astronomers Stunned as Epic Mars Aurora Covers Entire Planet
Yahoo
21-04-2025
- Science
- Yahoo
An AI Identifies Where All Those Planets That Could Host Life Are Hiding
Researchers in Switzerland have built an AI model to uncover potentially habitable worlds that are hiding from view. As detailed in a new study published in the journal Astronomy and & Astrophysics, the machine learning algorithm identified 44 star systems that it suspects harbor Earth-like exoplanets we haven't detected yet, in a promising demonstration of an approach that could accelerate the search for planets teeming with life. It hasn't outright confirmed that the Earth-like planets are actually there — but it's teed up astronomers to investigate those stellar neighborhoods in the future. In simulations, the model achieved an impressive precision value of up to 0.99, meaning that 99 percent of the systems identified have at least one Earth-like planet. "It's one of the few models worldwide with this level of complexity and depth, enabling predictive studies like ours," co-author Dr. Yann Alibert, codirector of the University of Bern's Centre for Space and Habitability, said in a statement, as quoted by Forbes. "This is a significant step in the search for planets with conditions favorable to life and, ultimately, for the search for life in the universe." Exoplanets are notoriously difficult to spot, because they're tiny compared to stars and produce little light of their own. So far, scientists have confirmed the existence of just over 5,800 planets outside our solar system — and the data we have on most of these is scant. That doesn't give a lot of material to train a pattern-seeking algorithm on, which require huge data sets. Instead, the astronomers fed their model synthetic planetary systems generated with the Bern Model of Planet Formation and Evolution, which comprehensively simulates the development of hypothetical planets as far back to their inception from a protoplanetary disc. "The Bern Model is one of the only models worldwide that offers such a wealth of interrelated physical processes and enables a study like the current one to be carried out," Alibert said in a statement about the research. During these tests, the AI model revealed that the strongest indicators of an Earth-like planet could be found in a system's innermost detectable planet, particularly its mass and orbital period, the researchers wrote in the study. From there, the team applied the machine learning algorithm to a sample of nearly 1,600 systems with at least one known planet and either a G-type, K-type, or M-type star, with G-types being Sun-like stars, and the remaining two classifications describing stars that are smaller and cooler. That revealed that nearly four dozen of them likely harbor an Earth-like world. But the model isn't infallible. It hasn't reproduced certain characteristics of star systems that astronomers have observed, such as the strong correlation between so-called Super Earths and Cold Jupiters, which often appear together around Sun-like stars, the authors note. And the synthetic planets tend to be found closer to their stars than real ones. Still, it doesn't need to be perfect: anything to narrow down astronomers' hunt for Earth's cousins through the the unfathomably vast cosmos could be a gamechanger. More on exoplanets: James Webb Space Telescope Captures Images of Individual Planets in Distant Star System
Yahoo
20-04-2025
- Science
- Yahoo
An AI Identifies Where All Those Planets That Could Host Life Are Hiding
Researchers in Switzerland have built an AI model to uncover potentially habitable worlds that are hiding from view. As detailed in a new study published in the journal Astronomy and & Astrophysics, the machine learning algorithm identified 44 star systems that it suspects harbor Earth-like exoplanets we haven't detected yet, in a promising demonstration of an approach that could accelerate the search for planets teeming with life. It hasn't outright confirmed that the Earth-like planets are actually there — but it's teed up astronomers to investigate those stellar neighborhoods in the future. In simulations, the model achieved an impressive precision value of up to 0.99, meaning that 99 percent of the systems identified have at least one Earth-like planet. "It's one of the few models worldwide with this level of complexity and depth, enabling predictive studies like ours," co-author Dr. Yann Alibert, codirector of the University of Bern's Centre for Space and Habitability, said in a statement, as quoted by Forbes. "This is a significant step in the search for planets with conditions favorable to life and, ultimately, for the search for life in the universe." Exoplanets are notoriously difficult to spot, because they're tiny compared to stars and produce little light of their own. So far, scientists have confirmed the existence of just over 5,800 planets outside our solar system — and the data we have on most of these is scant. That doesn't give a lot of material to train a pattern-seeking algorithm on, which require huge data sets. Instead, the astronomers fed their model synthetic planetary systems generated with the Bern Model of Planet Formation and Evolution, which comprehensively simulates the development of hypothetical planets as far back to their inception from a protoplanetary disc. "The Bern Model is one of the only models worldwide that offers such a wealth of interrelated physical processes and enables a study like the current one to be carried out," Alibert said in a statement about the research. During these tests, the AI model revealed that the strongest indicators of an Earth-like planet could be found in a system's innermost detectable planet, particularly its mass and orbital period, the researchers wrote in the study. From there, the team applied the machine learning algorithm to a sample of nearly 1,600 systems with at least one known planet and either a G-type, K-type, or M-type star, with G-types being Sun-like stars, and the remaining two classifications describing stars that are smaller and cooler. That revealed that nearly four dozen of them likely harbor an Earth-like world. But the model isn't infallible. It hasn't reproduced certain characteristics of star systems that astronomers have observed, such as the strong correlation between so-called Super Earths and Cold Jupiters, which often appear together around Sun-like stars, the authors note. And the synthetic planets tend to be found closer to their stars than real ones. Still, it doesn't need to be perfect: anything to narrow down astronomers' hunt for Earth's cousins through the the unfathomably vast cosmos could be a gamechanger. More on exoplanets: James Webb Space Telescope Captures Images of Individual Planets in Distant Star System
