Latest news with #IRAS
Yahoo
20-05-2025
- Science
- Yahoo
James Webb Space Telescope discovers an alien planetary system's icy edge
When you buy through links on our articles, Future and its syndication partners may earn a commission. At long last, particles of water–ice have been discovered in the frozen Kuiper Belt of another star. The discovery, made by the James Webb Space Telescope, is a major step forward in filling in gaps in our understanding of how exoplanets develop. Like the Kuiper Belt in our solar system, this extraterrestrial debris disk is likely filled with comets, dwarf planets and a lot of water-ice particles chipped off larger bodies as the result of collisions. The debris disk, also like our Kuiper Belt, is made up of remnants of a larger disk that once encircled the star — called HD 181327 — and probably gave birth to planets. To be clear, however, no planets in the region have been detected thus far. Because water is one of the most common molecules in the universe, its presence in HD 181327's debris disk is not a surprise. Indeed, exocomets have been detected around other stars; in our solar system, comets come from the frigid, icy Kuiper Belt and the Oort Cloud, so exocomets must originate from somewhere similar. However, while debris disks around other stars have been known about and imaged ever since the Infrared Astronomy Satellite (IRAS) found debris disks around two nearby stars (Vega and beta Pictoris) a while back, we've not had an instrument able to detect water-ice within them until now. Using the James Webb Space Telescope (JWST) and its Near-Infrared Spectrometer (NIRSpec), astronomers led by Chen Xie of Johns Hopkins University in the United States probed the debris disk around HD 181327. The star and its debris disk have previously been well-studied. Located 155.6 light-years away, they are just 18.5 million years old. This is extremely young compared to our sun's age of 4.6 billion years. The star is an F-type, meaning it's a little hotter and slightly more massive than our sun. NIRSpec detected the signature water in HD 181327's spectrum, principally at a wavelength of 3 microns (millionths of a meter), with a peak coming at 3.1 microns. This spike in the spectrum, referred to as a "Fresnel peak," is caused by the refraction of light by water-ice particles that are just millimeters in size. This is similar in size to the icy particles in Saturn's rings, for example, and the ice is likely frozen around motes of interplanetary dust. "Basically, we detected a water–ice reservoir," Xie told This water–ice reservoir could be instrumental in the development of any planetary system that might exist around HD 181327. Gas giant planets, for example, form beyond a boundary called the snow line, which is the distance from a star where temperatures are cold enough for planet-forming material to contain water-ice. Water-ice helps material stick together in a giant kind of mush that can form the basis of a large, rocky planetary core that can then pull in gas to form the distended atmosphere of a giant planet. The water on terrestrial planets such as Earth also likely was delivered by asteroids and/or comets that formed beyond the snow line and are rich in water-ice. Therefore, the discovery of water-ice in HD 181327's debris disk means the materials are present there to aid in the development of any planets orbiting the star, although at this time no planets have yet been detected in the system. "The presence of a water-ice reservoir in the planetesimal belt around HD 181327 provides the potential to deliver water to nearby planets," said Xie. "But we don't know how much water-ice could eventually be delivered to the planets in the system." It's tempting to make comparisons between our Kuiper Belt and HD 181327's debris disk. Xie warns about being too literal in the comparison, though, because there are significant gaps in our knowledge of both icy belts and how they relate to each other. Nevertheless, we can draw some general conclusions. "The presence of water-ice in a debris disk around such a young star does suggest that icy planetesimals can form relatively quickly, so it's possible that icy bodies in our own Kuiper Belt could have formed early in the cold outer regions of the solar system," he said. Their early existence could have then helped in the development of the solar system's planets. However, the planet-forming disk around HD 181327 has now dissipated, and any planets that are present will have already formed. Furthermore, the JWST's observations show how the inner region of the debris disk is being eroded by the star's ultraviolet light. The strength of the spectral line for water-ice at the inner edge of the debris disk, 80 to 90 astronomical units (meaning 80 to 90 times Earth's distance from the sun), suggests water-ice makes up just 0.1% of the total mass in that part of the disk. Farther out, between 90 and 105 astronomical units, the water-ice mass fraction rises to 7.5%, and between 105 and 120 astronomical units it peaks at 21%, out where it is coldest. Coincidentally, the Fresnel peak is found between 90 and 105 astronomical units. So, what's going on? Ultraviolet light from the star is able to vaporize the water-ice, but something seems to be replenishing it — otherwise, the water-ice in the debris disk would have eroded away by now. This replenishment likely comes from collisions between dwarf planets, cometary nuclei, micrometeoroids and other flotsam and jetsam lurking in the dark of the debris disk. Each impact sputters more dust and ice grains into space, and each large impact sends a shower of fragments spinning away. If there's enough dust present, it could also shield water-ice from the star's ultraviolet light. Dust that has been detected already includes grains of olivine and iron sulfide. Related Stories: — 2nd Kuiper Belt? Our solar system may be much larger than thought — Hubble Telescope discovers a new '3-body problem' puzzle among Kuiper Belt asteroids (video) — New JWST observations of 'trans-Neptunian objects' could help reveal our solar system's past Meanwhile, the Atacama Large Millimeter/submillimeter Array (ALMA), which is a radio telescope in Chile, has detected carbon monoxide in the debris disk, which could also have been released into space by collisions between icy bodies. In addition, the JWST's NIRSpec found tentative evidence for the presence of carbon dioxide in the region of the disk between 105 and 120 astronomical units from the star, although this still needs to be confirmed. A second spectral line for water-ice, at 4.5 microns, was also detected by the JWST in the 105 to 120 astronomical-unit region, indicating this outer part of the debris disk might be the most rich in volatiles: gases with low evaporation points. Now that the JWST has demonstrated that it can detect water-ice in exoplanetary systems, we can expect more widespread discoveries in the future. Indeed, Xie and his team are already working on it. "Besides HD 181327, we have also observed other systems with the JWST and NIRSPec," he said. "We're currently working on publishing those data, so stay tuned!" The discovery of water-ice around HD 181327 was published on May 14 in the journal Nature.
Yahoo
04-05-2025
- Science
- Yahoo
A strange object 65 billion miles from sun could be the elusive Planet Nine
Just because Pluto was ruled out as a planet in 2006 doesn't mean our solar system only has eight planets. The search for Planet Nine is far from over as scientists continue to uncover clues suggesting something massive may still be lurking in the distant dark beyond Neptune. Now, a team of international scientists has identified a promising Planet Nine candidate by comparing infrared surveys of the sky taken with a 23-year gap. The object appears to have shifted position over time, just what is expected from a distant planet slowly orbiting the sun. This is probably the most convincing evidence for Planet Nine so far. It is believed that this planet is five to ten times bigger than Earth and has an orbit wildly different from the known planets. In 2021, British astronomer Michael Rowan-Robinson combed through old data from NASA's Infrared Astronomical Satellite (IRAS), which scanned the sky in 1983. He spotted a possible Planet Nine candidate with an estimated mass of three to five times that of Earth at around 225 AU from the sun (1 AU is the Earth-sun distance). However, that object wasn't seen in any other dataset and remains unconfirmed. Recently, Patrick Phan (lead researcher of the current study) and his team took a new approach. They matched IRAS data with images from Japan's AKARI satellite, taken in 2006. In one IRAS image, they spotted an object. It wasn't in the same place when AKARI later looked, but AKARI did detect an object just 47.4 arcminutes (a bit less than one degree) away, consistent with how far Planet Nine could have drifted in its orbit over 23 years. This kind of motion is crucial because if something is moving that slowly, it's likely very far away and possibly orbiting the sun. What makes this finding stronger than earlier ones is that it shows up in two different infrared sky surveys—IRAS and AKARI—taken decades apart. Based on how bright the object appears in both datasets, the researchers estimate it could be even more massive than Neptune. That's surprising because the team was originally looking for something smaller—maybe a super-Earth. Yet, it fits the expectations for Planet Nine's estimated mass and distance better than anything found so far. Moreover, its suspected orbit is wildly different from the known planets. While Neptune orbits the sun at 30 AU (about 4.5 billion kilometers), Planet Nine might swing between 280 (closest distance from the sun) and 1,120 AU (farthest distance), up to 105 billion kilometers (65 billion miles) away. That's over 700 times farther than the sun is from Earth. Such a bizarre orbit raises many questions: Did this planet form with the rest of the solar system? Or was it captured from another star long ago? The possibility of finding a new planet in our own solar system is thrilling. If confirmed, Planet Nine would be the first planet discovered in modern times that wasn't found by accident or by studying close-up orbits. It would be revealed through indirect evidence, almost like spotting a ghost by the way it moves things around. However, the current study only suggests a possible candidate, and further evidence is needed to confirm its existence. 'The verification of Planet Nine's existence via future observational studies will contribute to our understanding of the evolution and structural dynamics of the solar system,' the study authors note. Unfortunately, NASA's more recent WISE (Wide-field Infrared Survey Explorer) sky surveys didn't pick up this object, but Phan suggests that this might be because the planet has moved from its 2006 position. Without knowing its exact orbit, it's impossible to say where it is now. He is hopeful that future observations will validate the findings from his research. The study will soon be published in the journal Publications of the Astronomical Society of Australia.
Time of India
03-05-2025
- Science
- Time of India
A 9th planet in our solar system? Scientists finally find a potential candidate to ‘replace' Pluto
The empty seat on the 9th row might just be filled! There possibly is a 9th planet after all (and a replacement for Pluto )! Researchers have *finally* found a candidate for the hypothetical Planet Nine , which could be an undiscovered giant planet way out in our solar system. Read on to find out more about the potential candidate! The 9th planet! It's been almost two decades since our solar system lost its 9th planet. Pluto was officially reclassified from a planet to a dwarf planet by the International Astronomical Union (IAU) in August 2006. While Pluto orbits the Sun and is large enough to be spherical due to gravity, it is not big enough to gravitationally dominate its orbital region, meaning other objects share its path in the Kuiper Belt. Pluto was reclassified as a dwarf planet in 2006 by the IAU because it failed to meet the third criterion for being a planet: it did not "clear its neighborhood" around its orbit. Nearly two decades after that, astronomers claim that they may have found new evidence that points to a celestial body that could be a possible candidate as "Planet Nine," according to a new paper, which has been accepted for publication in the Publications of the Astronomical Society of Australia but not yet peer-reviewed. What do the researchers say? Astronomers engaged in the search for a hypothetical ninth planet in our solar system have identified a promising candidate situated well beyond Neptune, according to a recent preprint study. This finding may represent the first substantial evidence of the long theorized Planet Nine, which, if confirmed, would be a large, yet-to-be-discovered world orbiting the sun at a considerable distance. However, the prospect of Planet Nine remains a debated topic within the scientific community, and skepticism surrounds the new findings. The potential planetary candidate was detected while researchers analyzed archival data from two decommissioned satellites: the Infrared Astronomical Satellite (IRAS), operational in 1983, and the AKARI satellite, which functioned from 2006 to 2011. The team was specifically looking for distant objects exhibiting slow movement characteristic of a large planet's orbit. After dismissing known celestial objects, they focused on a shortlist of candidates and ultimately identified what they referred to as "one good candidate." This candidate appeared as a consistent dot in infrared images from both satellites, indicative of a single object. Study lead author Terry Phan, a doctoral student in astronomy at the National Tsing Hua University in Taiwan, expressed excitement over the discovery, noting its motivational impact on the research team. Their findings were shared on the preprint server arXiv on April 24 and have been accepted for publication in the journal Publications of the Astronomical Society of Australia. Who is the potential candidate for the 9th planet? According to the paper, the hidden candidate is likely the size of Neptune and is so far away that it could take between 10,000 and 20,000 years to orbit the sun. The criteria to be a Planet: For a celestial body to be classified as a planet, the IAU defines, it must meet three criteria: it must orbit a star, it must be massive enough to have achieved hydrostatic equilibrium (meaning it is round or nearly round), and it must have cleared its orbital neighborhood, meaning it is the dominant gravitational body in its orbit. Is Planet Nine the replacement for Pluto? Despite this progress, some experts remain unconvinced. Notably, Caltech astronomer Mike Brown, who originally proposed the Planet Nine hypothesis alongside a colleague in 2016, has expressed doubts regarding the infrared signals' connection to the elusive planet. Brown analyzed the orbit of the candidate and concluded that its tilt—approximately 120 degrees from the Solar System's plane—deviates significantly from the predicted tilt for Planet Nine, which should be around 15 to 20 degrees. This discrepancy suggests the object may not significantly influence the orbits of other known planets. The predictive position of Planet Nine is designed to account for the irregular orbits observed among some objects in the Kuiper Belt at the outer edges of our solar system. However, many researchers contest the notion that an undiscovered planet is responsible for these anomalies, and direct observational evidence for Planet Nine's existence remains elusive. If Planet Nine does exist, predictions indicate that it would be considerably larger than Earth, orbiting the sun in a distant and unusual path. The vast distance from the sun makes detection particularly challenging, complicating efforts to confirm or refute its existence. Follow-up observations are necessary to refine the orbit of the identified candidate. Brown has suggested that if the infrared signal indicates a planet, it would contradict the existence of the originally hypothesized Planet Nine, as their orbits would likely destabilize each other. Evidence of ninth planet found in solar system
Yahoo
02-05-2025
- Science
- Yahoo
Astronomers Have Found a Prime Candidate for the Elusive Planet 9
Scientists examined infrared space surveys to narrow down candidates for Planet 9. Planet 9 would be so far from the Sun that it is just not illuminated by much sunlight. The two space surveys, conducted 23 years apart, could show how a secret planet orbits. Since the demotion of Pluto to dwarf planet, there's been a ninth-planet-shaped hole in the hearts of many Earthlings. How will we remember what My Very Excellent Mother Just Served Us now?Well, if we're lucky, we may soon be able to fill that gap. For some time now, scientists have wondered if a regular planet—not a dwarf planet—could explain some of the clustering of objects in the Kuiper Belt that starts at Neptune and extends outward from our Solar System. (Pluto is considered a Kuiper Belt object.) This hypothetical Planet 9 has never been directly observed and remains theoretical, but in new research uploaded to the preprint site arXiV, scientists share a very educated guess about the location of the long-theorized celestial body. (This study is not yet peer reviewed, but it follows a presentation from a 2024 conference and is listed as 'Accepted for publication in Publications of the Astronomical Society of Australia (PASA).') To search for Planet 9, the scientists 'search[ed] for objects that moved slowly between IRAS and AKARI detections.' IRAS and AKARI are far-infrared, all-sky surveys completed 23 years apart. Though Planet 9 has never been confirmed, we know a lot about what a planet in its suspected area could be like. The team used qualities like this—such as a very long orbit around the Sun, feasible temperatures, and probable masses—to narrow down the IRAS dataset and the AKARI dataset separately. They then highlighted 13 total bodies that fit the criteria and showed up in both datasets, accounting for changes in epochs and positions in orbit. From there, they inspected the surveys' images and found one eligible bachelor... er, planet. The scientists are careful to explain that the criteria they chose would not necessarily identify the only possible candidates for Planet 9. For instance, if Planet 9 is over the size constraints they placed on their study, it's still likely to be picked up at some point by infrared surveys like this. It could also be a gas giant-type planet on par with or larger than Neptune. But if it's smaller, it's likely below the threshold of observability at such a long range. And long range is, honestly, underselling it—top theories for the positioning of Planet 9 place it around 400 astronomical units (AU). The furthest known planet, Neptune, is only about 31 AU. That's already 31 times further than Earth is from the Sun, creating an orbit that lasts about 165 years. Planet 9 would also have an irregular orbit, scientists believe, so it would spent part of its cycle even further away. This is why two surveys conducted 23 years apart may just be the perfect way to observe Planet 9. In that amount of time, the planet itself will have completed just a tiny fraction of its overall orbit—enough to travel from one spot into the adjacent spot on the subsequent survey. But a lot of other factors would need to line up exactly in order for this candidate to be the real Planet 9, and the scientists are transparent about that. 'The finalist of our Planet Nine candidate pair strongly depends on how the characteristics of Planet Nine are defined. [I]f the actual mass of Planet Nine is not sufficient to make its flux above the detection limits of two surveys, there is no chance of finding Planet Nine in this work.' This group took a stab at observing Planet 9 using the IRAS and AKARI infrared surveys, which can 'see' further than telescopes using the visible spectrum. And indeed, while the odds of actually finding the elusive planet here may be more like the odds of buying a winning lottery ticket, the work opens several next steps for other teams investigating Planet 9. The data may also help narrow down parameters for those using other tools. 'If the existence of Planet Nine can be confirmed by observations in the near future, it will improve our understanding of the history and structure of the entire Solar System in early stages,' the team concludes. And it would get Pluto yet another big sibling. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
02-05-2025
- Science
- Yahoo
Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart
When you buy through links on our articles, Future and its syndication partners may earn a commission. The best candidate yet for the elusive Planet Nine has been spotted in two deep infrared surveys taken 23 years apart. If this mystery object really is Planet Nine, it would have a mass greater than Neptune, and currently be about 700 times farther from the sun than Earth is. The possibility of additional planets in our solar system has been proposed many times, going under names such as "Planet X," because experts thought the concept of an extra planet in our vicinity of the cosmos could explain a perceived regularity in mass extinctions on Earth. Perhaps, they said, the periodic influx of comets that impact Earth are pushed our way by an unseen planet. However, the supposed periodicity in mass extinctions has not held up to scrutiny, and so the need for that particular Planet X has gone away. This brings us to Planet Nine. Planet Nine is unrelated to the Planet X concept, and rather put forward in 2016 by Michael Brown and Konstantin Batygin of the California Institute of Technology to explain an unusual bunching of orbits of some objects in the Kuiper Belt, such as Sedna. This proposed Planet Nine would be more massive than Earth, and orbit on a highly eccentric path that takes it hundreds of astronomical units from the sun (one astronomical unit is the distance between Earth and the sun). That far away, it would be extremely difficult to detect. However, the expectation is that Planet Nine would appear brighter in mid- and far-infrared light than it would in visible light. Now, a team led by astronomer Terry Long Phan of the National Tsing Hua University in Taiwan has delved into the archives of two far-infrared all-sky surveys in search of Planet Nine — and incredibly, they have found something that could possibly be Planet Nine. The Infrared Astronomy Satellite, IRAS, launched in 1983 and surveyed the universe for almost a year before being decommissioned. Then, in 2006, the Japanese Aerospace Exploration Agency (JAXA) launched AKARI, another infrared astronomy satellite that was active between 2006 and 2011. Phan's team were looking for objects that appeared in IRAS's database, then appeared to have moved by the time AKARI took a look. The amount of movement on the sky would be tiny — about three arcminutes per year at a distance of approximately 700 astronomical units (AU). One arcminute is 1/60 of an angular degree. But there's an extra motion that Phan's team had to account for. As the Earth orbits the sun, our view of the position of very distant objects changes slightly in an effect called parallax. It is the same phenomenon as when you hold your index finger up to your face, close one eye and look at your finger, and then switch eyes — your finger appears to move as a result of you looking at it from a slightly different position. Planet Nine would appear to move on the sky because of parallax as Earth moves around the sun. On any particular day, it might seem to be in one position, then six months later when Earth is on the other side of the sun, it would shift to another position, perhaps by 10 to 15 arcminutes — then, six months after that, it would seem to shift back to its original position. To remove the effects of parallax, Phan's team searched for Planet Nine on the same date every year in the AKARI data, because on any given date it would appear in the same place, with zero parallax shift, every year. They then also scrutinized each candidate object that their search threw up on an hourly basis. If a candidate is a fast-moving, nearby object, then its motion would be detectable from hour to hour, and could therefore be ruled out. This careful search led Phan's team to a single object, a tiny dot in the infrared data. It appears in one position in IRAS's 1983 image, though it was not in that position when AKARI looked. However, there is an object seen by AKARI in a position 47.4 arcminutes away that isn't there in the IRAS imagery, and it is within the range that Planet Nine could have traveled in the intervening time. In other words, this object has moved a little further along its orbit around the sun in the 23 or more years between IRAS and AKARI. The knowledge of its motion in that intervening time is not sufficient to be able to extrapolate the object's full orbit, therefore it's not yet possible to say for certain whether this is Planet Nine. First, astronomers need to recover it in more up-to-date imagery. "Once we know the position of the candidate, a longer exposure with the current large optical telescopes can detect it," Phan told "However, the follow-up observations with optical telescopes still need to cover about three square degrees because Planet Nine would have moved from the position where AKARI detected it in 2006. This is doable with a camera that has a large field of view, such as the Dark Energy Camera, which has a field of view of three square degrees on the Blanco four-meter telescope [in Chile]." Based on the candidate object's brightness in the IRAS and AKARI images, Phan estimates that the object, if it really is Planet Nine, must be more massive than Neptune. This came as a surprise, because he and his team were searching for a super-Earth-size body. Previous surveys by NASA's Wide-field Infrared Survey Explorer (WISE) have ruled out any Jupiter-size planets out to 256,000 AU, and any Saturn-size planets out to 10,000 AU, but a smaller Neptune or Uranus-size world could still have gone undetected. Phan told that he had searched for his candidate in the WISE data, "but no convincing counterpart was found because it has moved since the 2006 position," and without knowing its orbit more accurately, we can't say where it has moved to. Another mystery is how Planet Nine, if it is real, ended up on an orbit that potentially brings it as close as 280 AU and as distant as 1,120 AU, which is far beyond the realm of the other planets. For comparison, the outermost planet, Neptune, is 30 AU (2.8 billion miles, or 4.5 billion kilometers) from the sun. At 700 AU, Planet Nine would be 65 billion miles (105 billion kilometers) from the sun. "One possibility is that Planet Nine formed closer to the sun, perhaps near the region where Jupiter, Saturn, Uranus and Neptune formed, and was later gravitationally scattered outward by one or more of these giant planets during the early days of the solar system," said Phan. Alternatively, perhaps it was a rogue planet picked up by the sun, maybe early in the history of the solar system when the sun was still close to its siblings and planets could be ejected and captured by different systems. RELATED STORIES: — Evidence for Planet 9 found in icy bodies sneaking past Neptune — A 'Planet Nine' far from Earth could explain the odd behavior of icy bodies beyond Neptune — Does Planet Nine really exist? This is not the first time that a candidate for Planet Nine has been found in infrared data. In 2021, astronomer Michael Rowan–Robinson of Imperial College, London, found an object in the IRAS data that had an estimated three to five Earth masses, and was much closer to the sun at about 225 AU. However, the detection has not been confirmed, and has not been made in any other dataset, such as by AKARI. Phan believes his candidate has a much better claim to being Planet Nine because it was detected by both IRAS and AKARI. Whether it really is Planet Nine, only time will tell. With the Nancy Grace Roman Space Telescope soon to launch to perform high-resolution deep surveys of the sky, and the Vera C. Rubin Observatory set to see first light this year, as well as the prowess of the already-established Dark Energy Camera, then if Planet Nine exists it is running out of places to hide. The candidate object is reported by Phan's team in a paper accepted for publication in Publications of the Astronomical Society of Australia.
