Planet Found in the Habitable Zone of a White Dwarf

An artist’s impression of the white dwarf star WD1054–226 orbited by clouds of planetary debris and a major planet in the habitable zone. Credit Mark A. Garlick / markgarlick.com Licence type Attribution (CC BY 4.0)

Most stars will end their lives as white dwarfs. White dwarfs are the remnant cores of once-luminous stars like our Sun, but they’ve left their lives of fusion behind and no longer generate heat. They’re destined to glow with only their residual energy for billions of years before they eventually fade to black.

Could life eke out an existence on a planet huddled up to one of these fading spectres?

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Astronomers Discover a Totally New Kind of Nebula

Discovery image of the nebula. For this image, 120 individual exposures had to be combined to obtain a total exposure time of 20 hours. The images were taken over several months from Brazil. Image Credit: Maicon Germiniani

Most Universe Today readers are familiar with nebulae. They’re gaseous structures lit up with radiation from nearby stars, and they’re some of nature’s most beautiful forms.

With the help of amateur astronomers who laid the groundwork, an international team of astronomers have discovered a new type of nebulae around binary stars that they’re calling galactic emission nebulae.

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From the way These Stars Look, a Supernova is Inevitable

Sometimes loud explosions are easier to deal with when you know they’re coming.  They are also easier to watch out for.  So when astronomers from the University of Warwick found a rare tear-drop shaped star, known as HD265435, they knew they were looking at a potential new supernova waiting to happen.  The only caveat – it might not actually happen until 70 million years from now.

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White Dwarf Measured Before it Exploded as a Supernova

Artist's impression of a supernova remnant. Credit: ESA/Hubble

Type Ia supernovae are an important tool for modern astronomy. They are thought to occur when a white dwarf star captures mass beyond the Chandrasekhar limit, triggering a cataclysmic explosion. Because that limit is the same for all white dwarfs, Type Ia supernovae all have about the same maximum brightness. Thus, they can be used as standard candles to determine galactic distances. Observations of Type Ia supernova led to the discovery of dark energy and that cosmic expansion is accelerating.

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How can White Dwarfs Produce Such Powerful Magnetic Fields?

Illustration of the internal layers of a white dwarf star. Credit: University of Warwick/Mark Garlick

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.

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

Illustration of the internal layers of a white dwarf star. Credit: University of Warwick/Mark Garlick

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.

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

A planet orbiting a small star produces strong atmospheric signals when it passes in front, or “transits,” its host star, as pictured above. White dwarfs offer astronomers a rare opportunity to characterize rocky planets. Image Credit: Jack Madden/Carl Sagan Institute

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.

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There’s a flash of ultraviolet just as a white dwarf is exploding as a supernova

Artist's impression of a supernova. Credit: NASA

Astronomers recently spotted a rare type of supernova explosion that was accompanied by a massive flare of ultraviolet radiation. Untangling the mystery of the UV flash could help unravel the mysterious nature of these supernova explosions, and even help us understand the age of the universe.

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

The material ejected by the supernova will initially expand very rapidly, but then gradually slow down, forming an intricate giant bubble of hot glowing gas. Eventually, the charred remains of the white dwarf that exploded will overtake these gaseous layers, and speed out onto its journey across the Galaxy. Credit: University of Warwick/Mark Garlick

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.

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