White dwarf Archives - Universe Today

September 29, 2021September 29, 2021

Aging White Dwarfs Become Even More Magnetic

In a few billion years the Sun will end its life as a white dwarf. As the Sun runs out of hydrogen to fuse for energy it will collapse under its own weight. Gravity will compress the Sun until it’s roughly the size of Earth, at which point a bit of quantum physics will kick in. Electrons from the Sun’s atoms will push back against gravity, creating what is known as degeneracy pressure. Once a star reaches this state it will cool over time, and the once brilliant star will eventually fade into the dark.

September 9, 2021September 8, 2021

White Dwarfs can Continue Burning Hydrogen, Even After They’re Dead

White dwarfs are supposed to be dead remnants of stars, doomed to simply fade away into the background. But new observations show that some are able to maintain some semblance of life by wrapping themselves in a layer of fusing hydrogen.

July 12, 2021July 12, 2021

A Nearby White Dwarf Might be About to Collapse Into a Neutron Star

About 97% of all stars in our Universe are destined to end their lives as white dwarf stars, which represents the final stage in their evolution. Like neutron stars, white dwarfs form after stars have exhausted their nuclear fuel and undergo gravitational collapse, shedding their outer layers to become super-compact stellar remnants. This will be the fate of our Sun billions of years from now, which will swell up to become a red giant before losing its outer layers.

Unlike neutron stars, which result from more massive stars, white dwarfs were once about eight times the mass of our Sun or lighter. For scientists, the density and gravitational force of these objects is an opportunity to study the laws of physics under some of the most extreme conditions imaginable. According to new research led by researchers from Caltech, one such object has been found that is both the smallest and most massive white dwarf ever seen.

May 11, 2021May 10, 2021

How can White Dwarfs Produce Such Powerful Magnetic Fields?

White dwarfs have some surprisingly strong magnetic fields, and one team of astronomers may have finally found the reason why. When they cool, they can activate a dynamo mechanism similar to what powers the Earth’s magnetic field.

February 1, 2021February 1, 2021

White Dwarf Atmospheres Might Contain the Pulverized Crusts of Their Dead Planets

Astronomers have developed a new technique to search for exoplanets – by looking for their crushed up bones in the atmospheres of white dwarfs. And it’s working.

January 21, 2021January 21, 2021

Strange Green Star is the Result of a Merger Between two White Dwarfs

A white dwarf isn’t your typical kind of star. While main sequence stars such as our Sun fuse nuclear material in their cores to keep themselves from collapsing under their own weight, white dwarfs use an effect known as quantum degeneracy. The quantum nature of electrons means that no two electrons can have the same quantum state. When you try to squeeze electrons into the same state, they exert a degeneracy pressure that keeps the white dwarf from collapsing.

December 12, 2020December 12, 2020

Is There a way to Detect Strange Quark Stars, Even Though They Look Almost Exactly Like White Dwarfs?

The world we see around us is built around quarks. They form the nuclei of the atoms and molecules that comprise us and our world. While there are six types of quarks, regular matter contains only two: up quarks and down quarks. Protons contain two ups and a down, while neutrons contain two downs and an up. On Earth, the other four types are only seen when created in particle accelerators. But some of them could also appear naturally in dense objects such as neutron stars.

September 17, 2020September 17, 2020

James Webb Will Look for Signs of Life on Planets Orbiting Dead Stars

Can the galaxy’s dead stars help us in our search for life? A group of researchers from Cornell University thinks so. They say that watching exoplanets transit in front of white dwarfs can tell us a lot about those planets.

It might even reveal signs of life.

August 24, 2020August 24, 2020

Scientists Recreate the Density of a White Dwarf in the Lab

The density of a white dwarf star defies our imagination. A spoonful of white dwarf matter would weigh as much as a car on Earth. Atoms within the star are squeezed so tightly that they are on the edge of collapse. Squeeze a white dwarf just a bit more, and it will collapse into a neutron star. And now, we can recreate the density of a white dwarf within a lab.

July 20, 2020July 20, 2020

A Star had a Partial Supernova and Kicked Itself Into a High-Speed Journey Across the Milky Way

Supernovae are some of the most powerful events in the Universe. They’re extremely energetic, luminous explosions that can light up the sky. Astrophysicists have a pretty good idea how they work, and they’ve organized supernovae into two broad categories: they’re the end state for massive stars that explode near the end of their lives, or they’re white dwarfs that draw gas from a companion which triggers runaway fusion.

Now there might be a third type.