All posts tagged: Hubble

“One bad measurement” ruled out as Hubble tension explanation

“One bad measurement” ruled out as Hubble tension explanation

Published by Jenni Sidey

For 15 years now, the expanding Universe hasn’t added up. This graph shows a comparison between the value of H0, or the expansion rate today, as derived from Hubble Space Telescope Cepheids and anchors as well as other subsamples of JWST Cepheids (or other types of stars) and anchors. A comparison to Planck, which uses the early relic method instead of the distance ladder method, is also shown. Very clearly, the distance ladder and early relic methods do not yield mutually compatible results. Credit: A.G. Riess et al., Astrophysical Journal submitted, arXiv:2408.11770, 2024 Different measurement methods should converge on the same answer. A large class of early relic methods, involving either the CMB and/or BAO (with a specific focus on DESI publications), all favor a Universe expanding at ~67 km/s/Mpc. Although there are a few groups that have outlier values for distance ladder measurements (including the CCHP group, shown as the second-from-bottom point), the strongest measurements, from the SH0ES and Pantheon+ collaborations, for instance, favor a value of ~73 km/s/Mpc, as shown here with smaller …

Scientists Startled by What Happens When They Point Hubble at Comet

Scientists Startled by What Happens When They Point Hubble at Comet

Published by José Betancourt

Sign up to see the future, today Can’t-miss innovations from the bleeding edge of science and tech Lady Fortune was on astronomers’ side when they pointed the Hubble Space Telescope at a comet drifting through our solar system. Just as they began observing the comet, it started breaking apart, providing an extraordinary chance to probe how these icy bodies evolve. “Sometimes the best science happens by accident,” John Noonan, a research physicist at Auburn University in Alabama, and coauthor of a new study published in the journal Icarus detailing the discovery, said in a statement about the work. After their original plans to observe a different comet fell through, “we had to find a new target,” he explained. “And right when we observed it, it happened to break apart, which is the slimmest of slim chances.” Shortly before disintegrating, the comet, dubbed  C/2025 K1 (ATLAS) — a home-grown snowball, not to be confused with our interstellar visitor 3/I ATLAS — had completed its closest approach to the Sun, a point called perihelion, on October 8, …

Ancient Milky Way stars challenge the age of the universe and the Hubble tension

Ancient Milky Way stars challenge the age of the universe and the Hubble tension

Published by Jenni Sidey

The oldest stars in the Milky Way are forcing a fresh look at one of cosmology’s biggest arguments. If some of them are about 13.6 billion years old, as a new analysis suggests, then the universe itself cannot be younger than that. That matters because astronomers still disagree on how fast the universe is expanding, a dispute known as the Hubble tension. One set of measurements, based on Cepheid stars and supernovae, points to a faster expansion rate and a younger universe, roughly 12.9 billion years old. Another, based on the cosmic microwave background, points to a slower expansion rate and an older universe, around 14.0 billion years old. The new study, published in Astronomy & Astrophysics, does not try to settle that argument by measuring expansion directly. Instead, researchers from the University of Bologna, the Leibniz Institute for Astrophysics Potsdam, and other institutes turned the problem into an age question: how old are the oldest stars close to home? Reading time in the Milky Way The logic is simple. The universe cannot be younger …

Hubble Spots Bizarre Galaxy That Appears to Be 99.9 Percent Dark Matter

Hubble Spots Bizarre Galaxy That Appears to Be 99.9 Percent Dark Matter

Published by José Betancourt

Sign up to see the future, today Can’t-miss innovations from the bleeding edge of science and tech The universe is overrun with dark matter, outweighing the ordinary stuff that stars and planets are made of five-to-one. But some corners of the cosmos are more dominated by the invisible substance than others. Using the stalwart Hubble Space Telescope, a team of astronomers have found a galaxy 300 million light away that appears to be made of at least 99.9 percent dark matter — so much that the galaxy is barely visible at all, they report in a new study published in The Astrophysical Journal Letters. The tenebrous realm, dubbed CDG-2, could be one of the most dark matter heavy galaxies ever found, and a compelling candidate for elusive and yet hypothetical “dark galaxies” that astronomers have been searching for for decades, which are thought to contain vanishingly few, if any, stars. “To be technically correct, CDG-2 is an almost-dark galaxy,” explained study lead author Dayi Li, an astrophysicist at the University of Toronto, in an interview …

Hubble Telescope Entering “Death Spiral”

Hubble Telescope Entering “Death Spiral”

Published by José Betancourt

Sign up to see the future, today Can’t-miss innovations from the bleeding edge of science and tech For years now, NASA’s Hubble Space Telescope has had its fair share of brushes with death. The groundbreaking observatory launched into low-Earth orbit 36 years ago, and it’s now been operational two decades longer than its expected lifespan, delivering a treasure chest of invaluable scientific insights that have greatly expanded our understanding of the universe. But time hasn’t been kind to the telescope. It’s been in and out of “safe mode” several times, had computer glitches bring it to its knees, and even started teetering thanks to most of its six gyros designed to keep it stabilized breaking down. Most severely of all, its orbit has steadily decayed, foreshadowing its ultimate demise as much of it burns up in the Earth’s atmosphere and any remains plummet to the planet below. For decades, Hubble has circled our planet in a circular low-Earth orbit at an altitude of approximately 340 miles. But how much longer it will be able to …

Nearly invisible galaxy may be built mostly of dark matter, Hubble finds

Nearly invisible galaxy may be built mostly of dark matter, Hubble finds

Published by Jenni Sidey

A tight clump of four star clusters sits in the Perseus galaxy cluster, and at first glance it looks like nothing special. No bright spiral arms. No obvious central bulge. Not even the soft smudge you would expect from a faint dwarf galaxy. That emptiness is the point. Astronomers say those four globular clusters, plus an almost ghostly halo of starlight around them, mark the location of an “almost dark” galaxy, one that carries a huge load of dark matter while forming very few stars. The object is called Candidate Dark Galaxy-2, or CDG-2, and it may be among the most extreme examples yet of a galaxy where the usual luminous stuff barely registers. Finding a galaxy by its leftovers CDG-2 did not announce itself through a patch of diffuse light, the way many ultradiffuse galaxies were first found in the last decade. Instead, it appeared as a statistical signal, a suspiciously tight overdensity of globular clusters that did not seem attached to any normal, bright galaxy. The low-surface-brightness galaxy CDG-2, shown in this image …

Last gasps of dying Sun-like star captured by Hubble

Last gasps of dying Sun-like star captured by Hubble

Published by Jenni Sidey

One of the most important lessons we learn from studying the Universe is that none of the sources of light that we see — none of the stars, galaxies, stellar remnants, quasars, or heated matter — will continue to shine forever. After a finite amount of time, anything powered by nuclear fusion or infalling matter will run out of fuel. Anything that emits light because it’s hot will cool, and once it’s cooled enough, it won’t emit detectable light signatures any longer: not only ultraviolet and visible light, but infrared, microwave, and even radio emissions will eventually cease. Every point-like and every extended light source, even though they shine brilliantly and ubiquitously today, will someday be snuffed out. For stars, there are three main fates that a star can have, all of which are heavily dependent on their mass at birth. The most massive stars will burn through their fuel and undergo collapse: either direct collapse to a black hole or core-collapse, leading to a supernova. These stars can leave black holes, neutron stars, or …

AI Tool Uncovers Hundreds of Hidden Cosmic Oddities in Hubble Data

AI Tool Uncovers Hundreds of Hidden Cosmic Oddities in Hubble Data

Published by Jenni Sidey

A team of astronomers based at the European Space Agency demonstrated how artificial intelligence technology will alter existing methods of locating rare astronomical phenomena within our galaxy, the Milky Way, and beyond. David O’Ryan and Pablo Gómez designed an artificial intelligence-assisted technique that can quickly sift through the huge number of images produced by several decades of observations from the Hubble Space Telescope. Using this technique, O’Ryan and Gómez discovered more than 1,300 previously unanticipated exotic stellar systems or other astronomical phenomena that had not been previously described in the scientific literature. Much of the research utilized the Hubble Legacy Archive (HLA), which over the past 35 years has collected vast amounts of space-based astronomical data from tens of thousands of distinct observing programs. In the HLA, there are close to 100 million so-called “cutouts,” or small sections of the night sky captured by Hubble. Each cutout may contain one distant galaxy or another extended astronomical object. A human being would take many lifetimes to review all of these cutouts visually. Archival observations provided by …

AI Discovers Hundreds of Anomalies in Archive of Hubble Images

AI Discovers Hundreds of Anomalies in Archive of Hubble Images

Published by José Betancourt

The universe is unfathomably vast, and for the astronomers trying to understand it, that means having to gather a commensurately mind-boggling amount of data. Wouldn’t it be nice if there was something that could help speed through looking for patterns in all the trillions of galaxies out there, and their quadrillions of stars? The term “AI” has become a catch-all these days for all kinds of dubious tech of varying degrees of automation and reliability, but certain types have found a very practical and welcome use among astronomers. Using a custom-built AI tool, for instance, a team of scientists at the European Space Agency have identified over a thousand “anomalies” in an archive of Hubble space telescope images that have gone unnoticed for decades, according to a NASA release. Their work, described in a new study published in the journal Astronomy & Astrophysics, is the first systematic search for astrophysical anomalies across the entire archive. “Archival observations from the Hubble Space Telescope now span 35 years, offering a rich dataset in which astrophysical anomalies may …

Hubble spots three young stars going through growth spurts

Hubble spots three young stars going through growth spurts

Published by Jenni Sidey

Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. NASA’s Hubble Space Telescope has captured a trio of young stars in the process of becoming their best selves in the constellation Scorpius. Posted to the agency’s site on January 16 as part of its Hubble Stellar Construction Zones series, the three T Tauri stars—seen at the bottom right, upper center, and left along with many other stellar objects in the background—are forming inside the hazy Lupus 3 cloud about 500 light-years from Earth. While the image appears somewhat serene, the interior forces at play are anything but tranquil.  A T Tauri star is a young star, usually less than 10 million years old. During this phase, the still-growing stellar object sees the dust and gas surrounding it begin to disappear as stellar winds, radiation, and other ionized particles bombard it. This dynamic environment is reflected in the star’s brightness, which randomly fluctuates depending on the material interactions underway in its accretion disk. More regular shifts in brightness can …