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Chance observations corroborate hybrid explanation for drop in brightness.

A weather satellite has helped explain why the red supergiant star Betelgeuse experienced an unprecedented dimming in 2019–20.

Its findings corroborate earlier studies that concluded the dimming was the consequence of a lower-temperature spot on the star, which reduced the heat going to a nearby gas cloud. This, astronomers believe, allowed the cloud to cool and condense into dust that blocked some of Betelgeuse’s light.

Continue reading “Weather satellite sheds light on ‘Great Dimming’ of Betelgeuse star” »

An interdisciplinary team led by Boston College physicists has discovered a new particle—or previously undetectable quantum excitation—known as the axial Higgs mode, a magnetic relative of the mass-defining Higgs Boson particle, the team reports in the online edition of the journal Nature.

The detection a decade ago of the long-sought Higgs Boson became central to the understanding of mass. Unlike its parent, axial Higgs mode has a magnetic moment, and that requires a more complex form of the theory to explain its properties, said Boston College Professor of Physics Kenneth Burch, a lead co-author of the report “Axial Higgs Mode Detected by Quantum Pathway Interference in RTe3.”

Theories that predicted the existence of such a mode have been invoked to explain “dark matter,” the nearly invisible material that makes up much of the universe, but only reveals itself via gravity, Burch said.

Understanding the early universe has been a goal for scientists for decades. And, now with NASA’s James Webb space telescope, and other technology, we’re finally making some decent strides. A new simulation on early galaxy formation could be another key stepping stone, too.

Researchers created the simulation using machine learning. It then completed over 100,000 hours of computations to create the one-of-a-kind simulation. The researchers named the algorithm responsible for the project Hydo-BAM. They published a paper with the simulation’s findings earlier this year.

Creating a simulation of early galaxy formation has allowed researchers to chart the earliest moments of our universe. These important moments began just after the Big Bang set everything into motion. Understanding these key moments of the formation of the early universe could help us better understand how galaxies form in the universe today.

All cosmic objects are embedded in magnetic fields. However, these fields are weak, but they are dynamically significant because they have profound effects on the dynamics of the universe.

The origin of these cosmic magnetic fields remains one of the most fundamental mysteries in cosmology, despite decades of intensive attention and inquiry.

By studying the dynamics of plasma turbulence, scientists from MIT are helping to solve one of the mysteries of the origins of cosmological magnetic fields.

Distinctive features of gravitational-wave signals from black hole mergers could reveal the existence of long-sought ultralight bosons.

A team of astronomers in Japan, for the first time, discovered a faint radio emission covering a giant galaxy as a result of achieving high imaging dynamic range. Radio emission is emitted by the gas created directly by the central black hole.

Using the same technique to additional quasars, the team hopes to learn more about how a black hole interacts with its host galaxy.

Using the Atacama Large Millimeter/submillimeter Array in Chile (ALMA), astronomers targeted the quasar 3C 273, which lies at 2.4 billion light-years from Earth. It is the first quasar ever discovered, the brightest, and the best studied. However, much less has been known about its host galaxy itself because combining the faint and diffuse galaxy with the 3C273 nucleus required such high dynamic ranges to detect.

A new technique locates stellar objects that change brightness.

Scientists have measured an upper-bound to the size of the Universe using the Cosmic Microwave Background (CMB) temperature gradient field [1]. The results show that the universe is most likely multiply connected, which means that it is finite, and the topology is such that it closes back in on itself—such that on the largest scale the universe has the geometry of a torus (and has a global positive curvature). This is contrary to the conventional cosmological models of the universe that model it as spatially infinite and topologically flat—assumed parameters that the researchers of the latest study demonstrate do not match the CMB temperature gradient data.

If the universe were spatially infinite and topologically flat, then the temperature fluctuations seen in the CMB would occur across all size scales—however this is not what is observed in the data. If, instead, the universe has a finite size and a multiply connected topology, like that of a torus, then in the early universe when the CMB was first emitted temperature fluctuations would be restricted in size since they could not be larger than the universe at that time. This would be observable in the extant CMB temperature gradient as a specific wave-length cut-off, which has now been described and demonstrated in a comprehensive analysis of the observed Planck CMB maps.

One of the researchers on the team that performed the study— astrophysicist Thomas Buchert, of the University of Lyon, Astrophysical Research Center in France— told Live Science in an email “We could say: Now we know the size of the universe” [2]. As reported by Live Science, Buchert further explained “In an infinite space, the perturbations in the temperature of the CMB radiation exist on all scales. If, however, space is finite, then there are those wavelengths missing that are larger than the size of the space.”

Neutron stars are normally extremely fast-spinning stellar corpses left over from the intense violence of a supernova, but researchers have found one in a “stellar graveyard” where one should not be – and it spins at a relatively glacial rate of once every 76 seconds.

Researchers with the University of Sydney found the bizarre radio signal, designated PSR J0901-4046, emitted by the neutron star thanks to the MeerKAT radio telescope in South Africa and weren’t even expecting to see it. The region of the sky they were observing was thought to be free of pulsars, since none had been observed there before.

Now they might know why. Capturing eight-second-long samples of the sky, they caught sight of a single pulse from the star, which had to be confirmed with subsequent observation due to its unexpectedly long rotational period.