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The Hindu
4 days ago
- Science
- The Hindu
IIST team discovers radio emission with circular polarisation near a massive young protostar
An international team led by astronomers from the Indian Institute of Space Science and Technology (IIST) here has discovered radio emission with a special property known as circular polarisation near a massive young protostar that is still forming about 4,500 light years from earth. [Protostar refers to the earliest known stage of a star when it is still accumulating gas and dust material from its surroundings.] The discovery linked to IRAS 18162-2048, a massive protostar in the Milky Way galaxy, opens an exciting window into scientists' understanding of how massive stars form, astronomers at the IIST said on Thursday. Circular polarisation occurs when electric and magnetic field vectors of electromagnetic waves—in this case radio waves—rotate in a circle about the direction in which the waves travel through space. This emission offers the first direct clue to the strength of magnetic fields in the immediate neighbourhood of a protostar, they said. The findings have been published in The Astrophysical Journal Letters under the title 'First Detection of Circular Polarization in Radio Continuum Toward a Massive Protostar.' In the early stage, the protostar can also eject high-velocity material in opposite directions, known as a bipolar jet. 'Massive protostars' evolve to have mass more than 8 to 10 times that of the Sun. Protostellar jets According to the astronomers, IRAS 18162-2048 powers one of the largest and brightest known protostellar jets in the Milky Way, the HH80-81 jet. It is believed that the magnetic field and rotation in the protostellar system are responsible for the ejection of the jet. While a magnetic field has been imaged from the jet earlier, this is the first time that hints of it have been detected directly from this massive protostar, according to the IIST. Strong magnetic fields have been observed earlier in low-mass protostars that go on to form stars like the Sun. But measuring such fields around massive protostars has remained elusive, until now. Much harder to study 'Massive protostars are much harder to study. The circular polarisation we are looking for is very faint and sporadic, making such measurements very challenging,' Amal George Cheriyan from the IIST, lead author of the paper, said in a statement. The radio observations were carried out using the National Radio Astronomy Observatory's (NRAO) Karl G. Jansky Very Large Array (VLA) in the U.S. 'This is the first inference of the magnetic field strength using circular polarisation in radio waves from a massive protostar,' said Sarita Vig of the IIST who conceptualised the work. Remarkable result 'The detection of circular polarisation is an exceptionally rare and challenging feat even in active galactic nuclei (AGNs), where conditions are extreme, but better investigated,' Nirupam Roy from the Indian Institute of Science (IISc), Bengaluru, said. Samir Mandal of the IIST noted that observing the phenomenon in the environment of a massive protostar, which lies buried in dense gas and dust, is even more difficult, making this result remarkable. The new data has allowed researchers to infer that the magnetic field near the protostar is roughly 100 times stronger than the Earth's magnetic field. They also support a long-standing theory that powerful jets from stars and black holes are driven by the same magnetic engine.
Arab Times
5 days ago
- Science
- Arab Times
Astronomers discover hidden alien planet 35 times heavier than Earth
NEW YORK, July 16: Astronomers have uncovered a previously undetected alien planet, Kepler-139f, by analyzing the orbits of known planets within the Kepler-139 star system. This hidden exoplanet is about twice the mass of Neptune and 35 times the mass of Earth, taking approximately 355 days to orbit its host star. The discovery was published on May 2, 2025, in The Astrophysical Journal Letters. Kepler-139f had managed to remain elusive due to limitations in early detection methods used by NASA's Kepler Space Telescope. Kepler, which identified nearly 3,000 exoplanets over its nine-year mission, primarily detected planets that passed directly between their star and Earth, causing a brief dimming of the star's light. This allowed scientists to identify the size of these planets. However, Kepler could not detect planets that were positioned above or below the line of sight of the telescope, meaning some planets remained hidden. However, because Kepler-139 is home to multiple planets, astronomers had the opportunity to search for worlds outside of Kepler's original detection range. The system was known to contain three rocky super-Earths that transit their star, and later, a fourth gas giant was discovered. Astronomers observed gaps in the orbits of these planets, suggesting the presence of an additional, unseen world. By studying these orbital gaps in detail, scientists were able to infer the existence of Kepler-139f. "The challenge isn't in finding non-transiting planets but in identifying situations where we can deduce the location of these hidden worlds," explained Caleb Lammers, a graduate student at Princeton University and co-author of the study. "It was through precise measurements of the known planets' orbits, including radial velocity (RV) and transit timing variations (TTVs), that we could infer the existence of Kepler-139f." The RV technique measures the gravitational pull a planet exerts on its host star, helping astronomers determine the planet's mass. Additionally, TTVs—subtle variations in the timing of transits of known planets—can indicate the presence of other planets that don't transit the star themselves. Lammers and his colleague, Joshua Winn, an astrophysicist at Princeton and participating scientist on the Kepler mission, worked together to identify these gaps in the system. Using a combination of RV and TTV measurements, the pair discovered Kepler-139f nestled between the outermost super-Earth and a gas giant in the system. Kepler-139f's discovery also provided clarity on the previously puzzling density of Kepler-139c, the outermost super-Earth in the system. The earlier density readings were incorrectly influenced by the pull of the hidden planet, but with Kepler-139f identified, the team revised the data, providing more typical density values for Kepler-139c. The discovery raises the possibility that other unseen planets may be lurking in the Kepler-139 system. "There may still be other undiscovered planets in the system, especially given the prominent gap between planets b and c," said Lammers. "The challenge now is to find them." While the Kepler and TESS (Transiting Exoplanet Survey Satellite) missions have been adept at detecting planets closer to their stars—where transits are more frequent and easier to observe—planets further away with wider orbits present more difficulties. Additionally, the RV method is more effective for detecting larger, more massive planets due to their stronger gravitational influence. This bias toward larger worlds has made it harder to detect smaller, more distant planets, particularly those that don't transit their stars. To combat these challenges, astronomers are combining multiple methods—transits, RVs, and TTVs—to identify smaller, hidden planets. "It's likely that many planetary systems host unseen worlds, particularly in their outer regions," Lammers added. Looking ahead, the European Space Agency's upcoming PLATO mission, launching in 2026, will provide an even more powerful tool for detecting these hidden planets. PLATO will survey transiting planets and revisit the Kepler field, refining TTV measurements and boosting the potential for discovering more misaligned and hidden worlds. "In the near future, TTV-based planet detection is expected to accelerate significantly with the PLATO mission," Lammers concluded.
Yahoo
6 days ago
- Science
- Yahoo
Astronomers discover giant alien planet 35 times more massive than Earth hiding in a known star system
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have detected a hidden alien planet by examining the orbits of the known worlds in the star system, known as Kepler-139. The newfound exoplanet, called Kepler-139f, is a gigantic world roughly twice the mass of Neptune and 35 times the mass of Earth, and it takes 355 days to orbit its star, astronomers reported in a study published May 2 in The Astrophysical Journal Letters. Despite its giant size, Kepler-139f had evaded detection. That's because the initial yield of NASA's Kepler space telescope, which discovered nearly 3,000 planets in its nine years of operation, relied on worlds transiting — passing between their star and Earth. The resulting dimming of the star allowed astronomers to identify planets and calculate their size. But Kepler couldn't see planets traveling above or below the wedge of space between it and the star, so any outliers remained unseen. But if the hidden world was part of a multiplanet system, astronomers could try to find it despite its inclined orbit. Kepler-139 has three rocky transiting super-Earths; a fourth gas giant was later discovered. Gaps in their orbits suggested that other worlds might be present. Precise measurements of the orbits allowed the astronomers to infer the existence of at least one more planet. "The issue is not exactly finding non-transiting planets, but rather, finding situations in which we can deduce where the non-transiting planet is located," Caleb Lammers, a graduate student in the Department of Astrophysical Science at Princeton and co-author of the study, told by email. Kepler's initial identification of a world was often followed up by observations from the ground. Using radial velocity (RV), astronomers could measure how much a planet tugged on its star, allowing them to determine the planet's mass. RV measurements could also reveal new worlds, as happened with the outermost gas giant, Kepler-139e. At the same time, each planet is pulled by not only its star but also by other planets in the system, regardless of whether that planet can be seen from Earth. These pulls can affect how swiftly a planet transits, thus creating "transit timing variations" (TTVs). These variations in the transiting planets can reveal worlds that don't cross the star. "When you observe TTVs that cannot be attributed to the known planets, you can be fairly confident that there is an unseen body in the system," Lammers said. Lammers and his colleague Joshua Winn, a participating scientist on the Kepler team and co-author of the study, went looking for gaps in known systems. Then, they used both RV and TTV measurements to hunt for a missing world, revising existing TTVs based on the 2023 discovery of Kepler-139e. "What was different in the case of Kepler-139 is that we had precise radial velocity observations which did not conclusively point towards a new planet on their own," Lammers said. Combined with the TTVs, the observations revealed a fifth planet, Kepler-139f, tucked between the outermost super-Earth and the gas giant. The new discovery also helped to answer a question about Kepler-139e. The original reports of Kepler-139c, the outermost super-Earth, provided an unusually large density for a sub-Neptune-size planet. The discrepancy occurred because those authors didn't know about Kepler139f, so they had attributed some of its pull on its star to Kepler-139c. The new data suggest a more typical density for Kepler-139c while leaving the densities for Kepler-139d and Kepler-139b essentially unchanged. These revisions provide indirect evidence for Kepler-139f, Lammers said. There may even be other hidden worlds around Kepler-139. "It remains possible that there are other unseen planets in the system," Lammers said, pointing to the prominent gap between planets b and c. "The challenge is finding them!" Both Kepler and NASA's more recent exoplanet hunting mission, the Transiting Exoplanet Survey Satellite (TESS), were sensitive to planets orbiting closer to their star. These inner worlds were more likely to make many transits, allowing scientists to confirm the planet's existence. But transiting planets with wider orbits made only a handful of passes, so they were more challenging to observe and confirm. At the same time, the RV method tends to be biased toward larger planets, because the more massive a world is, the stronger it tugs on its star. Proximity helps; the pull of the planet is amplified to the square inverse of its distance. Thus, a planet twice as far away will have only one-fourth the gravitational pull. That's why many of the first discovered exoplanets were Jupiter-size worlds that circled their star in only a few days. RELATED STORIES —Massive new NASA exoplanet catalog unveils 126 extreme and exotic worlds —25 years of exoplanet hunting hasn't revealed Earth 2.0 — but is that what we're looking for? —The 10 most Earth-like exoplanets All of these factors make it harder to discover smaller planets that are farther away, particularly if they don't transit their star. But by combining transits, RVs and TTVs, astronomers can find smaller, hidden worlds orbiting farther from their star. "It is likely that many planetary systems host unseen worlds, especially in their outer regions," Lammers said. But soon, it will be harder for those worlds to hide. In 2026, the European Space Agency will launch its Planetary Transits and Oscillations of Stars (PLATO) mission, which will conduct its own survey of transiting planets, as well as revisit Kepler's field. In providing additional transit times for planets detected by Kepler more than a decade later, PLATO will improve measurements of TTVs to enable the discovery of more misaligned worlds. "In the coming years, the TTV planet detection technique will probably be accelerated dramatically by the PLATO mission," Lammars said.
Yahoo
13-07-2025
- Science
- Yahoo
Mysterious Signals From Deep Space Hint at Something Brutal, Scientists Say
Astronomers believe they've uncovered the source behind mysterious cosmic signals known as fast X-ray transients (FXTs) — and it adds a grim twist to our understanding of the death of stars. Right as a massive star explodes in a supernova, it unleashes a tremendously energetic stream of particles called a jet, producing a gamma ray burst — one of the most powerful explosions in the universe. The rest of the star, typically, collapses into a black hole. But a pair of new studies suggests that this last gasp by a star before winking out of existence can get "trapped" by some of the star's own remains, slamming the door shut on the jet so it can't fully shine. "As the jet is being launched, that extra material from the star that didn't collapse into the black hole [interacts] with the jet in such a way that sort of suppresses the jet from actually breaking out of the outer layers," Jillian Rastinejad, an astronomer at Northwestern University and lead author of one the two studies set to published in the The Astrophysical Journal Letters, told Gizmodo. That produces the weaker X-ray emissions, in the form of an FXT, which can last from seconds to hours. The nickname astronomers have for these weakened blasts is nearly as brutal as the catastrophic event itself: a "failed" jet. According to the findings, FXTs arise from a type of stellar explosion called a Type Ic supernova, which occurs in stars that have long shed their outermost layers of hydrogen and helium. Because of their ephemeral nature and the extreme distance of most detected FXTs to date, pinpointing their origins has been a challenge for astronomers. Rastinejad and her team's breakthrough came when data collected in the Einstein Probe, an X-ray telescope program run by the Chinese Academy of Sciences in collaboration with the European Space Agency, revealed an FXT that was unusually close to Earth — a mere 2.8 billion light years away. Dubbed EP 250108a, telescopes including the Keck Observatory in Hawai'i and the James Webb Space Telescope rushed to extensively image the X-ray burst in multiple wavelengths, collecting infrared and optical data. "It's important to note that X-ray data alone cannot tell us what phenomena created an FXT," Rastinejad said in a statement about the work. "Rapid observations of the location of the FXT at optical and infrared wavelengths are key to identifying the aftermath of an FXT and assembling clues to its origin." With that wealth of data, the astronomers were able to observe how the signal evolved over time. Over the course of several weeks, the stunted supernova increased in brightness before eventually fading. The brief peak in brightness allowed the astronomers to determine that the blast was a Type Ic supernova — and one that was clearly lacking a gamma ray burst. This has profound implications for our understanding of a star's demise, because according to the work, with sufficiently large stars — the one that produced EP 250108a is estimated to be between 15 to 30 times heavier than the Sun — the full-blown gamma ray bursts we've come to equate with supernovas may not actually be the norm. Instead, Rastinejad said, "this 'trapped' jet outcome is more common in massive star explosions than jets that successfully emerge from the star." More on space: Astronomers Capture First-Ever Image of Star That Exploded Twice
New York Post
30-06-2025
- Science
- New York Post
Astronomers stumble upon ancient radio signals from distant galaxy cluster
Astronomers studying a distant galaxy cluster stumbled upon ancient radio signals that might hold clues to the formation of the early universe. While studying the distant galaxy cluster known as SpARCS1049, astronomers detected faint mysterious radio waves, according to a study published in TheAstrophysical Journal Letters and available on the pre-print server Xrxiv. The discovered radio waves, which took 10 billion years to reach Earth, originated from a vast region of space filled with high-energy particles and magnetic fields. These vast clouds of high-energy particles are known as a mini-halo. A mini-halo has never been detected this deep into space before, according to the study. Mini-halos are described in the study as faint groups of charged particles. These groups are known to emit both radio and X-ray waves. Mini-halos are typically found in clusters between galaxies. 4 The discovered radio waves originated from a vast region of space filled with high-energy particles and magnetic fields. Astrophysics of Galaxies Roland Timmerman of the Institute for Computational Cosmology of Durham University and co-author of the study said in a statement in how these particles are important for the creation of our universe. 'It's astonishing to find such a strong radio signal at this distance,' Timmerman said. 'It means these energetic particles and the processes creating them have been shaping galaxy clusters for nearly the entire history of the universe.' The astronomers analyzed data from the Low Frequency Array (LOFAR) radio telescope. The LOFAR is made up of 100,000 small antennas across eight European countries, according to the study. 4 A mini-halo has never been detected this deep into space before, according to the study. Astrophysics of Galaxies The team of astronomers believes there are two causes for the makeup of these mini-halos. According to the study, the first explanation is supermassive black holes found at the heart of galaxies. These black holes can release high-energy particles into space. The astronomers are perplexed as to how these particles would escape such a powerful black hole to create these clusters. 4 The LOFAR is made up of 100,000 small antennas across eight European countries, according to the study. Chandra X-ray Center The second explanation, according to the study, is cosmic particle collisions. These cosmic particle collisions occur when charged particles filled with hot plasma collide at near-light speeds. These collisions smash apart, allowing the high-energy particles to be observed from Earth. According to the study, astronomers now believe that this discovery suggests that either black holes or particle collisions have been energizing galaxies earlier than previously believed. 4 The astronomers are perplexed as to how these particles would escape such a powerful black hole to create these clusters. Astrophysics of Galaxies New telescopes being developed like the Square Kilometer Array will eventually let astronomers detect even more faint signals. Julie Hlavacek-Larrondo from the University of Montreal and co-lead author of the study said in a statement she believes this is just the beginning to the wonders of space. 'We are just scratching the surface of how energetic the early universe really was,' Hlavacek-Larrondo said in the statement. 'This discovery gives us a new window into how galaxy clusters grow and evolve, driven by both black holes and high-energy particle physics.' Nick Butler is a reporter for Fox News Digital. Do you have any tips? Reach out to
