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Observations by NASA’s James Webb Space Telescope are upending the understanding of the early universe, indicating the presence of large and mature but remarkably compact galaxies teeming with stars far sooner than scientists had considered possible.

Astronomers said data obtained by the telescope reveals what appear to be six big galaxies as mature as our Milky Way existing about 540 million to 770 million years after the explosive Big Bang that kicked off the universe 13.8 billion years ago. The universe was roughly 3 percent of its current age at the time.

These galaxies, one of which appears to have a mass rivaling our Milky Way but 30 times more densely packed, seem to differ in fundamental ways from those populating the universe today.

“Oh, they are radically different — truly bizarre creatures,” said astrophysicist Ivo Labbe of Swinburne University of Technology in Australia, lead author of the study published in the journal Nature. “If the Milky Way were a regular-sized average adult, say about 5 feet, 9 inch (1.75 meters) and 160 pounds (70 kg), these would be 1-year-old babies weighing about the same but standing just under 3 inches (7 cm) tall. The early universe is a freak show.”

Webb was launched in 2021 and began collecting data last year. The findings were based upon the first dataset released by NASA last July from Webb, a telescope boasting infrared-sensing instruments able to detect light from the most ancient stars and galaxies.

“This is an astounding discovery and unexpected. We thought that galaxies form over much longer periods of time,” said Penn State astrophysicist and study co-author Joel Leja. “No one expected to find these. These galaxy candidates are simply too evolved for our expectations. They seem to have evolved faster than allowed by our standard models.”

Leja called them galaxy candidates because further observations are needed to confirm that they all are galaxies rather than some other source of light like a supermassive black hole.

“The exciting part is that even if only some turn out to be massive galaxies, these things are so massive that they alone would upend our measurements of the total mass in stars at this time. It would suggest 10 to 100 times more mass in stars existing at this epoch than expected and would imply that galaxies form way, way faster in the universe than anyone thought.”

The galaxies appear to contain mass equivalent to 10 billion to 100 billion times that of our sun. The latter figure is similar to the Milky Way’s mass.

The journey to galaxy formation following the Big Bang apparently hinged on mysterious material called dark matter that is invisible to us but is known to exist because of the gravitational influence it exerts on normal matter.

“The leading theory is that an ocean of dark matter filled the early universe after the Big Bang,” Labbe said.

“This dark matter — we don’t know what it is actually is — started out really smooth, with only the tiniest of ripples. These ripples grew over time due to gravity and eventually the dark matter started to collect in concentrated clumps, dragging hydrogen gas along for the ride. It’s that hydrogen gas that will eventually turn into stars. Clumps of dark matter, gas and stars is what we call a galaxy,” Labbe added.

Astronomers suspect the first stars began forming 100 million to 200 million years after the Big Bang, each perhaps 1,000 more massive than our sun but much shorter-lived.

“Their explosion set off the chain of events that formed subsequent generations of stars,” Labbe said.

“Webb continuous to amaze and surprise us,” Labbe added. “So yes, the early universe was a lot richer and lot more diverse — monsters and dragons. And the curtain is still being lifted.”

© Thomson Reuters 2023


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A Nearby Supernova May End Dark Matter Search, Claims New Study

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A Nearby Supernova May End Dark Matter Search, Claims New Study

The pursuit of understanding dark matter, which comprises 85 percent of the universe’s mass, could take a significant leap forward with a nearby supernova. Researchers at the University of California, Berkeley, led by Associate Professor of Physics Benjamin Safdi, have theorised that the elusive particle known as the axion might be detected within moments of gamma rays being emitted from such an event. Axions, predicted to emerge during the collapse of a massive star’s core into a neutron star, could transform into gamma rays in the presence of intense magnetic fields, offering a potential breakthrough in physics.

Potential Role of Gamma-Ray Telescopes

The study was published in Physical Review Letters and revealed that the gamma rays produced from axions could confirm the particle’s mass and properties if detected. The Fermi Gamma-ray Space Telescope, currently the only gamma-ray observatory in orbit, would need to be pointed directly at the supernova, with the likelihood of this alignment estimated at only 10 percent. A detection would revolutionise dark matter research, while the absence of gamma rays would constrain the range of axion masses, rendering many existing dark matter experiments redundant.

Challenges in Catching the Event

For detection, the supernova must occur within the Milky Way or its satellite galaxies—an event averaging once every few decades. The last such occurrence, supernova 1987A, lacked sensitive enough gamma-ray equipment. Safdi emphasised the need for preparedness, proposing a constellation of satellites, named GALAXIS, to ensure 24/7 sky coverage.

Axion’s Theoretical Importance

The axion, supported by theories like quantum chromodynamics (QCD) and string theory, bridges gaps in physics, potentially linking gravity with quantum mechanics. Unlike neutrinos, axions could convert into photons in strong magnetic fields, providing unique signals. Laboratory experiments like ABRACADABRA and ALPHA are also probing for axions, but their sensitivity is limited compared to the scenario of a nearby supernova. Safdi expressed urgency, noting that missing such an event could delay axion detection by decades, underscoring the high stakes of this astrophysical endeavour.

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Fastest-Moving Stars in the Galaxy May be Piloted by Aliens, New Study Suggests

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Fastest-Moving Stars in the Galaxy May be Piloted by Aliens, New Study Suggests

Intelligent extraterrestrial civilisations might be utilising stars as massive interstellar vehicles to explore the galaxy, according to a theory proposed by Clement Vidal, a philosopher at Vrije Universiteit Brussel in Belgium. His research suggests that alien species could potentially accelerate their binary star systems to traverse vast cosmic distances. While such a concept is purely hypothetical and unproven, Vidal’s recent paper, which has not undergone peer review, raises intriguing possibilities about advanced extraterrestrial engineering.

Concept of Moving Star Systems

The study was published in the Journal of the British Interplanetary Society. As per a report by LiveScience, the idea revolves around the notion that alien civilisations, instead of building spacecraft for interstellar travel, might manipulate entire star systems to travel across the galaxy. Vidal highlights binary star systems, particularly those involving neutron stars and smaller companion stars, as ideal candidates. Neutron stars, due to their immense gravitational energy, could serve as anchors for devices designed to propel the system by selectively ejecting stellar material.

Vidal explained in the paper that uneven heating or manipulation of magnetic fields on a star’s surface could cause it to eject material in one direction. This process would create a reactionary thrust, propelling the binary system in the opposite direction. The concept provides a way to travel while preserving planetary ecosystems, making it a theoretically viable method for species reliant on their home systems.

Known Examples with High Velocities

Astronomers have identified hypervelocity stars, such as the pulsars PSR J0610-2100 and PSR J2043+1711, which exhibit high accelerations. While their movements are believed to be natural phenomena, Vidal suggests they could be worth further investigation to rule out potential artificial influences.

This theory adds an unconventional angle to the search for intelligent life, expanding possibilities beyond traditional methods of exploration like searching for signals or probes. The research underscores the importance of considering advanced and unconventional methods aliens might employ to navigate the galaxy.

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Hubble Telescope Finds Unexpectedly Hot Accretion Disk in FU Orionis

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Hubble Telescope Finds Unexpectedly Hot Accretion Disk in FU Orionis

NASA’s Hubble Space Telescope has provided new insights into the young star FU Orionis, located in the constellation Orion. Observations have uncovered extreme temperatures in the inner region of its accretion disk, challenging current models of stellar accretion. Using Hubble’s Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph, astronomers captured far-ultraviolet and near-ultraviolet spectra, revealing the disk’s inner edge to be unexpectedly hot, with temperatures reaching 16,000 kelvins—almost three times the Sun’s surface temperature.

A Star’s Bright Outburst Explained

First observed in 1936, FU Orionis became a hundred times brighter in months and has remained a unique object of study. Unlike typical T Tauri stars, its accretion disk touches the stellar surface due to instabilities. These are caused by the disk’s large mass, interactions with companion stars, or material falling inwards. Lynne Hillenbrand, a co-author from Caltech, in a statement said that the ultraviolet brightness seen exceeded predictions, revealing a highly dynamic interface between the star and its disk.

Implications for Planet Formation

As per a report by NASA, the study holds significant implications for planetary systems forming around such stars. The report further quoted Adolfo Carvalho, lead author of the study, saying that while distant planets in the disk may experience altered chemical compositions due to outbursts, planets forming close to the star could face disruption or destruction. This revised model provides critical insights into the survival of rocky planets in young star systems, he further added.

Future Investigations on FU Orionis

The research team continues to examine spectral emission lines in the collected data, aiming to map gas movement in the star’s inner regions. Hillenbrand noted that FU Orionis offers a unique opportunity to study the mechanisms at play in eruptive young stars. These findings, published in The Astrophysical Journal Letters, showcase the ongoing value of Hubble’s ultraviolet capabilities in advancing stellar science.

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