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Category: Astronomy/cosmology

Stars could be invisible within 20 years as light pollution brightens night skies

Stars could be invisible within 20 years as light pollution brightens night skies

Robin McKie writes: The Herefordshire hills basked in brilliant sunshine last weekend. Summer had arrived and the skies were cloudless, conditions that would once have heralded succeeding nights of coal-dark heavens sprinkled with brilliant stars, meteorites and planets. It was not to be. The night sky was not so much black as dark grey with only a handful of stars glimmering against this backdrop. The Milky Way – which would once have glittered across the heavens – was absent. Summer’s…

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The tiny physics behind immense cosmic eruptions

The tiny physics behind immense cosmic eruptions

Zack Savitsky writes: During fleeting fits, the sun occasionally hurls a colossal amount of energy into space. Called solar flares, these eruptions last for mere minutes, and they can trigger catastrophic blackouts and dazzling auroras on Earth. But our leading mathematical theories of how these flares work fail to predict the strength and speed of what we observe. At the heart of these outbursts is a mechanism that converts magnetic energy into powerful blasts of light and particles. This transformation…

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Gargantuan black hole 30 billion times the mass of the sun is one of the largest ever discovered

Gargantuan black hole 30 billion times the mass of the sun is one of the largest ever discovered

Live Science reports: Astronomers have discovered one of the largest black holes ever found — an ultramassive monster roughly 30 billion times the mass of the sun — using a space-time trick predicted by Albert Einstein. The colossal black hole, which lurks 2.7 billion light-years from Earth in the brightest galaxy of the galaxy cluster Abell 1201, was given away by a giant arc of warped light from a background galaxy that had been stretched and smudged by the black…

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The early universe was crammed with stars 10,000 times the size of our sun, new study suggests

The early universe was crammed with stars 10,000 times the size of our sun, new study suggests

Space.com reports: The first stars in the cosmos may have topped out at over 10,000 times the mass of the sun, roughly 1,000 times bigger than the biggest stars alive today, a new study has found. Nowadays, the biggest stars are 100 solar masses. But the early universe was a far more exotic place, filled with mega-giant stars that lived fast and died very, very young, the researchers found. And once these doomed giants died out, conditions were never right…

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Shadows in the Big Bang afterglow reveal invisible cosmic structures

Shadows in the Big Bang afterglow reveal invisible cosmic structures

Zack Savitsky writes: Nearly 400,000 years after the Big Bang, the primordial plasma of the infant universe cooled enough for the first atoms to coalesce, making space for the embedded radiation to soar free. That light — the cosmic microwave background (CMB) — continues to stream through the sky in all directions, broadcasting a snapshot of the early universe that’s picked up by dedicated telescopes and even revealed in the static on old cathode-ray televisions. After scientists discovered the CMB…

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The multiverse: Our universe is suspiciously unlikely to exist – unless it is one of many

The multiverse: Our universe is suspiciously unlikely to exist – unless it is one of many

Do universes pop up as bubbles from a multiverse? arda savasciogullari/Shutterstock By Martin Rees, University of Cambridge It’s easy to envisage other universes, governed by slightly different laws of physics, in which no intelligent life, nor indeed any kind of organised complex systems, could arise. Should we therefore be surprised that a universe exists in which we were able to emerge? That’s a question physicists including me have tried to answer for decades. But it is proving difficult. Although we…

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Rare black hole 1 billion times the mass of the sun could upend our understanding of galaxy formation

Rare black hole 1 billion times the mass of the sun could upend our understanding of galaxy formation

Space.com reports: A rare supermassive black hole found hiding at the dawn of the universe could indicate that there were thousands more of the ravenous monsters stalking the early cosmos than scientists thought — and astronomers aren’t sure why. The primordial black hole is around 1 billion times the mass of our sun and was found at the center of the galaxy COS-87259. The ancient galaxy formed just 750 million years after the Big Bang and was spotted by the…

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The giant arcs that may dwarf everything in the cosmos

The giant arcs that may dwarf everything in the cosmos

Jasmin Fox-Skelly writes: In 2021, British PhD student Alexia Lopez was analysing the light coming from distant quasars when she made a startling discovery. She detected a giant, almost symmetrical arc of galaxies 9.3 billion light years away in the constellation of Boötes the Herdsman. Spanning a massive 3.3 billion light years across, the structure is a whopping 1/15th the radius of the observable Universe. If we could see it from Earth, it would be the size of 35 full…

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Neutron stars: A form of matter like no other

Neutron stars: A form of matter like no other

Katia Moskvitch writes: On Aug. 6, 1967, Jocelyn Bell was looking at the squiggles drawn by a red pen on moving rolls of chart paper—the data from a radio telescope she was using to do her Ph.D. research on distant galaxies. She noticed one squiggle that looked odd. It was a “a bit of scruff,” she tells me from her office at Oxford University, where she’s now a visiting professor of astrophysics. The “scruff” was a series of sharp pulses…

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James Webb telescope spotted the earliest known ‘quenched’ galaxy

James Webb telescope spotted the earliest known ‘quenched’ galaxy

Science News reports: The James Webb Space Telescope has spotted the earliest known galaxy to abruptly stop forming stars. The galaxy, called GS-9209, quenched its star formation more than 12.5 billion years ago, researchers report January 26 at arXiv.org. That’s only a little more than a billion years after the Big Bang. Its existence reveals new details about how galaxies live and die across cosmic time. “It’s a remarkable discovery,” says astronomer Mauro Giavalisco of the University of Massachusetts Amherst,…

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The largest structures in the Universe are still glowing with the shock of their creation

The largest structures in the Universe are still glowing with the shock of their creation

Tessa Vernstrom using Planck data, Author provided By Tessa Vernstrom, The University of Western Australia and Christopher Riseley, Università di Bologna On the largest scales, the Universe is ordered into a web-like pattern: galaxies are pulled together into clusters, which are connected by filaments and separated by voids. These clusters and filaments contain dark matter, as well as regular matter like gas and galaxies. We call this the “cosmic web”, and we can see it by mapping the locations and…

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Astronomers say they have spotted the universe’s first stars

Astronomers say they have spotted the universe’s first stars

Jonathan O’Callaghan writes: A group of astronomers poring over data from the James Webb Space Telescope (JWST) has glimpsed light from ionized helium in a distant galaxy, which could indicate the presence of the universe’s very first generation of stars. These long-sought, inaptly named “Population III” stars would have been ginormous balls of hydrogen and helium sculpted from the universe’s primordial gas. Theorists started imagining these first fireballs in the 1970s, hypothesizing that, after short lifetimes, they exploded as supernovas,…

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Standard model of cosmology survives a telescope’s surprising finds

Standard model of cosmology survives a telescope’s surprising finds

Rebecca Boyle writes: The cracks in cosmology were supposed to take a while to appear. But when the James Webb Space Telescope (JWST) opened its lens last spring, extremely distant yet very bright galaxies immediately shone into the telescope’s field of view. “They were just so stupidly bright, and they just stood out,” said Rohan Naidu, an astronomer at the Massachusetts Institute of Technology. The galaxies’ apparent distances from Earth suggested that they formed much earlier in the history of…

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New data show that light pollution is rapidly obscuring the night sky

New data show that light pollution is rapidly obscuring the night sky

Science News reports: The night sky has been brightening faster than researchers realized, thanks to the use of artificial lights at night. A study of more than 50,000 observations of stars by citizen scientists reveals that the night sky grew about 10 percent brighter, on average, every year from 2011 to 2022. In other words, a baby born in a region where roughly 250 stars were visible every night would see only 100 stars on their 18th birthday, researchers report…

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Ancient humans and their early depictions of the universe

Ancient humans and their early depictions of the universe

Astronomy reports: In the Lascaux caves of southwestern France, which are famously adorned with 17,000-year-old paintings, the artist’s subject is almost always a large animal. But hovering above the image of one bull is an unexpected addition: a cluster of small black dots that some scholars interpret as stars. Perhaps it is the eye-catching Pleiades, which Paleolithic hunter-gatherers would have seen vividly in the unpolluted sky. Claims of prehistoric astronomy are controversial. Even if true, we frequently trace our cosmic…

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Inside ancient asteroids, gamma rays made building blocks of life

Inside ancient asteroids, gamma rays made building blocks of life

John Rennie and Allison Parshall write: In 2021, the Hayabusa2 space mission successfully delivered a morsel of the asteroid 162173 Ryugu to Earth — five grams of the oldest, most pristine matter left over from the solar system’s formation 4.5 billion years ago. Last spring, scientists revealed that the chemical composition of the asteroid includes 10 amino acids, the building blocks of proteins. The discovery added to the evidence that the primordial soup from which life on Earth arose may…

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