A Distant White Dwarf Is Eating a Jupiter-Sized Planet for Lunch

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Approximately 650 light-years away, within the constellation Aquarius, you’ll find the planetary nebula called Caldwell 63, or more famously known as the Helix Nebula. This is essentially the cooling remnants of a deceased star, a massive expanse of gas and debris that spans over 3 light-years in width.

At the heart of the nebula resides the white dwarf known as WD 2226-210, once the core of a star with an intermediate mass. For many decades, this celestial body has been a puzzling enigma in astronomy due to its peculiar high-energy X-ray emissions detected by space observatories such as Einstein, Chandra, and ROSAT.

Currently, scientists hypothesize that X-rays are generated as debris from a splintered planet impacts the white dwarf’s surface. A scholarly article detailing this discovery has been made available as a preprint and is set to be published in the Monthly Notices of the Royal Astronomical Society.

For More on Space

1. Parasitic Black Holes May Consume Some Stars (Even Our Sun) from Within: A Glimpse at Edge-of-Galaxy Star Formation – Here’s What They Look Like

2. Rapidly Growing Baby Stars on the Outskirts of Galaxies – Check Out Their Appearance!
The Blazing Star Erupts Every 80 Years – Here’s How to Witness It!

Both titles aim to convey the same content, but with a more natural and easy-to-read language. The first title focuses on parasitic black holes consuming stars (including the sun) from within, while highlighting that this happens at the edge of galaxies and providing a glimpse into their appearance. The second title emphasizes the rapid growth of baby stars on the outskirts of galaxies, mentioning one specific star’s periodic eruption and suggesting how to observe it.

A quiet stellar death: How white dwarf stars are made

As a medium-sized star similar to our Sun reaches its final days, it undergoes a dramatic transformation into a minuscule yet incredibly dense celestial behemoth known as a white dwarf. Throughout their lives, stars wage an eternal struggle between the inward pull of gravity and the outward force generated by core fusion of light elements. For much of their existence, this tug-of-war remains balanced, but near the end, gravity ultimately prevails, triggering a catastrophic collapse.

Over several decades, our studies alongside advanced space telescopes have unveiled cosmic spectacles similar to those depicted on SYFY’s “The Ark.” Based on the star’s mass, it can either collapse into a black hole, detonate in a supernova, or gradually shed its outer layers and transform into a white dwarf. Stars that are approximately eight times the size of our Sun, or less, will ultimately become white dwarfs. As it approaches its end, the star’s outer layers expand significantly, losing their gravitational pull to hold them together. These outer layers then peel off, spreading out across space, and giving rise to a planetary nebula. Meanwhile, the core contracts into a compact, hot, and dense object.

White dwarfs, which make up around half the total number of stars in our universe, have a mass similar to half that of our Sun but occupy an area approximately equal to Earth’s. This makes them among the most densely packed objects in existence, with a density roughly 200,000 times greater than Earth’s. Neutron stars and black holes are the only known denser entities. Their surface temperatures hover around 100,000 Kelvin (around 180,000 degrees Fahrenheit), cooling down gradually over a time span of about a billion years.

X-ray echoes show a white dwarf eating a planet in the Helix Nebula

White dwarfs typically don’t emit intense X-ray signals, leading astronomers to wonder if something peculiar was happening around WD 2226-210. Observations through telescopes revealed that the white dwarf’s X-ray emission stayed consistent from 1992 to 2002, with a faint, regular pattern every 2.9 hours. This recurring pattern hints at the potential presence of Jupiter-like planetary debris in an extremely tight orbit.

Dr. Martin Guerrero, an astronomer from the Institute of Astrophysics of Andalusia, speculated that the enigmatic signal we’ve observed could be due to remnants from a shattered planet colliding with a white dwarf’s surface and emitting X-rays as they heat up. This information was shared via Sci News.

It’s possible that the proposed planet initially orbited at a greater distance from the white dwarf, but due to interactions with other planets, it moved closer. As the planet approached the strong gravitational pull of the white dwarf, parts or even the entire planet could have been torn off or destroyed. The remnants might have formed a compact ring around the star, gradually falling onto its surface. If this theory is verified, it would mark the first instance where astronomers observe a planet being consumed by a white dwarf within a planetary nebula.

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2025-03-07 23:03