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Showing posts with the label big bang

Astronomers discover a brand-new type of astrophysical object: A black hole star

By Jennifer Chu | MIT News .  Excerpt: Astronomers at MIT and elsewhere have spotted an extremely bright red spot [that] resembles an enormous star, spanning the size of our solar system. But it also is putting out 100 billion times more energy than any known star can physically produce. ...astronomers are calling it a “black hole star.” In a paper appearing today in the journal Nature , the team presents their analysis of the new object, which they discovered using NASA’s James Webb Space Telescope (JWST). The telescope spotted the bright red dot in the very early universe, just a few hundred million years after the Big Bang. ...The object is likely a hugely dense cloud of gas, powered not by standard nuclear fusion, but by a central black hole ...100,000 times as massive as the sun....  Full article at https://news.mit.edu/2026/astronomers-discover-brand-new-type-astrophysical-object-black-hole-star-0812 .

Gravitational lensing could break the Hubble tension

By Science Advisor, AAAS.  Excerpt: ...The rate of cosmic expansion, known as the Hubble constant, is so important for cosmologists that the disagreement among researchers over its value has its own name: the Hubble tension. Astronomers measure it one way, using stars or supernovae with predictable brightness. Cosmologists have another way, studying ripples in the echo of the Big Bang and winding the clock forward to today. The two techniques have become increasingly precise, but they steadfastly disagree with each other. A third method is needed to  break the deadlock  . That may come through the magic of gravitational lensing, which can cause a supernova—a star exploding at the end of its life—to appear to explode again and again. If a supernova is situated behind a large mass, such as a galaxy or cluster of galaxies, then as its light passes by the mass, its gravity bends the light along different paths, producing multiple images that show the explosion at different ti...

JWST spots most distant galaxy ever, pushing the limits of the observable universe

By Jackie Flynn Mogensen , Scientific American.  Excerpt: The galaxy MoM-z14 could offer clues to what the universe looked like in its early infancy. ...On Wednesday astronomers on  announced that a bright galaxy  called MoM-z14 that was found using NASA’s  James Webb Space Telescope  (JWST) is the farthest yet detected, existing just 280 million years after the big bang. ...The galaxy, the light of which has taken more than 13 billion years to reach our telescopes, is  brighter, denser and more chemically rich than astronomers had expected , according to NASA....  Full article at https://www.scientificamerican.com/article/jwst-spots-most-distant-galaxy-ever-pushing-the-limits-of-the-observable/ . 

This ‘Galaxy That Wasn’t’ Never Bore Any Stars

By Katrina Miller , The New York Times.  Excerpt: This week, astronomers announced the discovery of a new kind of cosmic object, something that is very nearly a galaxy, save for one crucial, missing ingredient: stars. The almost-galaxy is about 14 million light-years from Earth. It was the ninth cloud found to be associated with a nearby spiral galaxy, leading to its serendipitous name: Cloud-9. The object is starless, consisting of only a haze of hydrogen gas that astronomers believe is swaddled in a much more massive clump of  dark matter,  the invisible substance that permeates the cosmos and shapes its overarching structure. ...Cloud-9 is the first confirmed example of what astronomers call a RELHIC, short for Reionization-Limited H I Cloud and pronounced “relic.” Such objects are rich in gaseous hydrogen but devoid of any stars. They are  failed galaxies  thought to be nearly as old as time itself, primordial fossils that can help astronomers understand the...

Stars made from only primordial gas finally spotted, astronomers claim

By Daniel Clery , Science.  Excerpt: Staring deep into space and far back in time, a team of astronomers may have spotted a galaxy full of stars made from only the primordial gas created in the Big Bang. Such “population III stars” would have formed from hydrogen and helium and nothing else, and researchers have been searching for them for decades.... If confirmed, the discovery, made with NASA’s JWST space observatory, opens a window on the starting point of the chemical enrichment of the universe, in which the heavier elements needed to make planets and life began to be forged in stellar explosions. ...The nature of population III stars remains uncertain. Most theorists think they were huge, with masses up to 1000 times that of the Sun, 10 times larger than any star around today. ...The gigantic stars that resulted would also burn hot and fast, ending in a supernova explosion after just a few million years. That brief first flash of population III stars is hard for astronomers to...

Piping Up at the Gates of Dawn

By Dennis Overbye , The New York Times.  Excerpt: Since the James Webb Space Telescope began operating two years ago, astronomers have been using it to leapfrog one another millions of years into the past, back toward the moment they call cosmic dawn, when the first stars and galaxies were formed. Last month, an international team doing research as the JWST Advanced Deep Extragalactic Survey, or JADES, said it had identified the earliest, most distant galaxy yet found — [JADES-GS-z14-0] a banana-shaped blob of color measuring 1,600 light-years across. It was already shining with intense starlight when the universe was in its relative infancy, at only 290 million years old, the astronomers said. ...the wavelength of light from JADES-GS-z14-0 had been stretched more than 15-fold by the expansion of the universe (a redshift of 14 to use astronomical jargon), similar to the way a siren’s pitch becomes lower as it speeds away. That means light has been coming toward us for 13.5 billion ...