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Category: Astronomy

The North Star has an age-defying secret: stellar cannibalism

The North Star has an age-defying secret: stellar cannibalism

Phil Plait writes: Polaris, the North Star, is one of the most famous stars in the sky, but it’s also quite an enigma. A recent reappraisal of its basics—such as its mass and distance from Earth—suggests that the star is paradoxically youthful, appearing to be only a small fraction of its true multi-billion-year age, like a middle-aged human who somehow passes for a toddler. This is deeply strange; you’d probably assume astronomers have simply miscalculated this star’s age. But in…

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Some of the universe’s oldest stars have been discovered in the Milky Way

Some of the universe’s oldest stars have been discovered in the Milky Way

Quartz reports: Some stars in our very own Milky Way are some of the earliest ever seen, according to research published today in the Monthly Notices of the Royal Astronomical Society. The stars are in the Milky Way’s halo, a shroud of stars that surrounds the galactic disk. The stars are also relatively close, at just 30,000 light-years from Earth. The team found that the stars are between 12 billion and 13 billion years old, clocking them to around the…

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The universe as a network of rivers

The universe as a network of rivers

The universe as a network of rivers: This remarkable new map reveals how galaxies flow like water, following the pull of gravity across hundreds of millions of light years. https://t.co/krsqjnnoa3 pic.twitter.com/192Q28SrM9 — Corey S. Powell (@coreyspowell) April 26, 2024 Astrobites reports: Cosmography is the science of cartography, but applied to the Universe by mapping out the Large Scale Structures such as voids, filaments and superclusters. While galaxy surveys are able to create such maps from just looking at spatial information…

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From 15 billion miles away, Voyager 1 resumes sending engineering updates to Earth

From 15 billion miles away, Voyager 1 resumes sending engineering updates to Earth

NASA reports: For the first time since November, NASA’s Voyager 1 spacecraft is returning usable data about the health and status of its onboard engineering systems. The next step is to enable the spacecraft to begin returning science data again. The probe and its twin, Voyager 2, are the only spacecraft to ever fly in interstellar space (the space between stars). Voyager 1 stopped sending readable science and engineering data back to Earth on Nov. 14, 2023, even though mission…

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Milky Way’s largest stellar black hole discovered 2,000 light years away from Earth

Milky Way’s largest stellar black hole discovered 2,000 light years away from Earth

The European Space Agency reports: Wading through the wealth of data from ESA’s Gaia mission, scientists have uncovered a ‘sleeping giant’. A large black hole, with a mass of nearly 33 times the mass of the Sun, was hiding in the constellation Aquila, less than 2000 light-years from Earth. This is the first time a black hole of stellar origin this big has been spotted within the Milky Way. So far, black holes of this type have only been observed…

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Solar eclipses are always with us

Solar eclipses are always with us

Marina Koren writes: Cosmically speaking, the alignment of Earth, the sun, and the moon is ordinary. But from our corner of the universe, the occurrence produces something wondrous: a total solar eclipse. On April 8, the moon will pass between the sun and Earth, casting a shadow along a narrow strip of the country, from Texas to Maine. Outside this path, the sun will not disappear, and the best and safest way to observe the event is with eclipse glasses….

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Planet-eating stars hint at hidden chaos in the Milky Way

Planet-eating stars hint at hidden chaos in the Milky Way

Nature reports: Stellar detectives have identified seven stars that recently dined on a rocky planet. The study doubles the number of binary stars known to have consumed a planet, and questions the perception that mature solar systems harbouring Earth-like planets are usually stable. The findings, published in Nature on 20 March, show “strong evidence of planet ingestion”, says Jianrong Shi, an astronomer at the National Astronomical Observatories in Beijing. The planets seem to have been eaten during their stars’ relatively…

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Do black holes explode? The 50-year-old puzzle that challenges quantum physics

Do black holes explode? The 50-year-old puzzle that challenges quantum physics

Davide Castelvecchi writes: In hindsight, it seems prophetic that the title of a Nature paper published on 1 March 1974 ended with a question mark: “Black hole explosions?” Stephen Hawking’s landmark idea about what is now known as Hawking radiation1 has just turned 50. The more physicists have tried to test his theory over the past half-century, the more questions have been raised — with profound consequences for how we view the workings of reality. In essence, what Hawking, who…

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We finally know what turned the lights on at the dawn of time

We finally know what turned the lights on at the dawn of time

Science Alert reports: We finally know what brought light to the dark and formless void of the early Universe. According to data from the Hubble and James Webb Space Telescopes, the origins of the free-flying photons in the early cosmic dawn were small dwarf galaxies that flared to life, clearing the fog of murky hydrogen that filled intergalactic space. “This discovery unveils the crucial role played by ultra-faint galaxies in the early Universe’s evolution,” says astrophysicist Iryna Chemerynska of the…

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JWST finds ancient galaxy larger than our Milky Way, and it’s threatening to upend cosmology

JWST finds ancient galaxy larger than our Milky Way, and it’s threatening to upend cosmology

Live Science reports: The James Webb Space Telescope (JWST) has found a galaxy in the early universe that’s so massive, it shouldn’t exist, posing a “significant challenge” to the standard model of cosmology, according to the study authors. The galaxy, called ZF-UDS-7329, contains more stars than the Milky Way, despite having formed only 800 million years into the universe’s 13.8 billion-year life span. This means they were somehow born without dark matter seeding their formation, contrary to what the standard…

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Several ingredients for life found on Enceladus, a small moon of Saturn

Several ingredients for life found on Enceladus, a small moon of Saturn

The New York Times reports: Scientists have detected a poison among the spray of molecules emanating from a small moon of Saturn. That adds to existing intrigue about the possibility of life there. The poison is hydrogen cyanide, a colorless gas that is deadly to many Earth creatures. But it could have played a key role in chemical reactions that created the ingredients that set the stage for the advent of life. “It’s the starting point for most theories on…

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Could the universe be finite?

Could the universe be finite?

Eric Schwitzgebel and Jacob Barandes write: On recent estimates, the observable universe—the portion of the universe that we can detect through our telescopes—extends about 47 billion light-years in every direction. But the limit of what we can see is one thing, and the limit of what exists is quite another. It would be remarkable if the universe stopped exactly at the edge of what we can see. For one thing, that would place us, surprisingly and un-Copernicanly, precisely at the…

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Scientists discover rare 6-planet system that moves in strange synchrony

Scientists discover rare 6-planet system that moves in strange synchrony

University of Chicago reports: Scientists have discovered a rare sight in a nearby star system: Six planets orbiting their central star in a rhythmic beat. The planets move in an orbital waltz that repeats itself so precisely it can be readily set to music. A rare case of an “in sync” gravitational lockstep, the system could offer deep insight into planet formation and evolution. The analysis, led by UChicago scientist Rafael Luque, was published Nov. 29 in Nature. “This discovery…

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Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Live Science reports: The supermassive black hole at the heart of our galaxy isn’t just spinning — it’s doing so at almost maximum speed, dragging anything near it along for the ride. Physicists calculated the rotational speed of the Milky Way’s supermassive black hole, called Sagittarius A* (Sgr A*), by using NASA’s Chandra X-ray Observatory to view the X-rays and radio waves emanating from outflows of material. The spin speed of a black hole is defined as “a” and given…

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‘Teenage’ galaxies from the early universe contain mysterious heavy elements, James Webb telescope reveals

‘Teenage’ galaxies from the early universe contain mysterious heavy elements, James Webb telescope reveals

Live Science reports: The deeper we look into space, the further back in time we see. Light emanating from some of the younger galaxies in our universe has to travel for billions of years to reach us, getting picked up by our instruments, rich with information from the cosmic dawn. And not only can this light tell us where we have come from, but where we might be headed. To understand the evolution of several of these early universe, “teenage”…

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Supernovae blasts struck the Earth 3 million and 7 million years ago

Supernovae blasts struck the Earth 3 million and 7 million years ago

Universe Today reports: A recent study examines how the Earth was hit by blasts from supernovae (plural form of supernova (SN)) that occurred 3 million years ago (Mya) and 7 Mya with the goal of ascertaining the distances of where these blasts originated. Using the live (not decaying) radioactive isotope 60-Fe, which is produced from supernovae, a team of researchers at the University of Illinois was able to determine the approximate astronomical distances to the blasts, which they refer to…

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