In a breakthrough study published in Nature Astronomy, researchers have discovered a new origin for some of the fastest stars ever observed: hypervelocity white dwarfs—compact stellar remnants hurtling through space faster than 2000 km/s.
Category: cosmology – Page 10
The unthinkable confirmed—James Webb and Hubble prove that the universe is expanding at two different speeds, throwing cosmology into crisis
Does it sound familiar to you the name James Webb? Maybe you’ve heard about it because it’s a very important telescope scientists use on its missions. Recently, this telescope and the Hubble have confirmed the universe is expanding in two different directions. I know it is difficult to believe, even scientists doubt it at first, but telescopes have proved it. So, let’s find out more about what the James Webb Space Telescope and the Hubble telescope have found.
To make this scientific explanation more visual, imagine you draw small dots on the surface of a deflated balloon and then you blow it up. What do you think will happen to the dots? Exactly! They will be far from each other because the balloon stretches.
So, this is what happens with the universe. Galaxies separate because space itself is expanding, and the speed this is occurring is called: the Hubble constant. You may not know this, but this is so important that it helps us know the age and destiny of the universe.
Revolutionary Model Reveals How Real Universe Structure Affects Cosmic Evolution
For nearly a century, cosmologists have relied on a simplified model of the universe that treats matter as uniform particles that don’t interact with each other. While this approach helped scientists understand the Big Bang and the expansion of space, it ignores a fundamental reality, that our universe is anything but uniform. Stars cluster into galaxies, matter collapses into black holes, and vast empty voids stretch across space, all constantly interacting through gravity and other forces.
Toward new physics: First-ever double crystal channeling observed
Might two bent crystals pave the way to finding new physics? The Standard Model of particle physics describes our world at its smallest scales exceptionally well. However, it leaves some important questions unanswered, such as the imbalance between matter and antimatter, the existence of dark matter and other mysteries.
One method to find “new physics” beyond the Standard Model is to measure the properties of different particles as precisely as possible and then compare measurement with theory. If the two don’t agree, it might hint at new physics and let us slowly piece together a fuller picture of our universe—like pieces of a jigsaw puzzle.
An example of particles that physicists wish to study more closely are “charm baryons” such as the “Lambda-c-plus” (Λc+) which is a heavier “cousin” of the proton, consisting of three quarks: one up, one down and one charm. These particles decay after less than a trillionth of a second (10-13 s), which makes any measurement of their properties a race against time. Some of their properties have not yet been measured to high precision, leaving room for new physics to hide.
International collaboration doubles detection of cosmic collisions
An international team of researchers has announced a significant advancement in gravitational-wave astronomy, with the detection of 128 new cosmic collisions involving black holes and neutron stars.
This discovery more than doubles the number of known gravitational-wave events and marks a major milestone in our understanding of the universe.
The findings come from the latest data release by the Laser Interferometer Gravitational-Wave Observatory (LIGO) Virgo Gravitational Wave Interferometer (Virgo) Kamioka Gravitational Wave Detector (KAGRA) collaboration, a global network of gravitational-wave observatories.
X-ray and Radio go ‘Hand in Hand’ in New Image
In 2009, NASA’s Chandra X-ray Observatory released a captivating image: a pulsar and its surrounding nebula that is shaped like a hand. Since then, astronomers have used Chandra and other telescopes to continue to observe this object. Now, new radio data from the Australia Telescope Compact Array (ATCA) has been combined with Chandra’s X-ray data to provide a fresh view of this exploded star and its environment, to help understand its peculiar properties and shape.
At the center of this new image lies the pulsar B1509-58, a rapidly spinning neutron star that is only about 12 miles in diameter. This tiny object is responsible for producing an intricate nebula (called MSH 15–52) that spans over 150 light-years, or about 900 trillion miles. The nebula, which is produced by energetic particles, resembles a human hand with a palm and extended fingers pointing to the upper right in X-rays.
The collapse of a massive star created the pulsar when much of the star crashed inward once it burned through its sustainable nuclear fuel. An ensuing explosion sent the star’s outer layers outward into space as a supernova.
The Star That Almost Vanished: Astronomers Solve a Cosmic Mystery
Stars often reach the end of their lives and fade from view, but astronomers were left baffled when a star that had remained steady for more than ten years suddenly seemed to vanish for nearly eight months.
From late 2024 through early 2025, a star in our galaxy known as ASASSN-24fw lost about 97% of its brightness before returning to normal. The unusual dimming quickly became the subject of debate as researchers searched for an explanation behind such an extraordinary event.
An international research team, led by scientists at The Ohio State University, now believes they may have solved the puzzle. In a study recently published in The Open Journal of Astrophysics, the group reports that because the star’s color did not change during the dimming, the cause was unlikely to be related to stellar evolution. Instead, they conclude that a massive cloud of dust and gas surrounding the star blocked it from Earth’s view.