In a cosmic crime scene some 255 light-years from Earth, astronomers say they have found a white dwarf star devouring what appears to be a Pluto-like icy world. The discovery, made using the Hubble Space Telescope, shines fresh light on how planetary systems evolve—and how the remnants of planets can end up being consumed long after they were born.
The culprit at the center of this drama is a dense stellar remnant, a white dwarf, whose intense gravity is now eating the broken fragments of an icy body. The chemical make-up of the debris, especially the unusually high nitrogen levels, points to an object rich in ices—very different from the mostly rocky bodies we’ve seen being torn apart before.
Astronomers led by Snehalata Sahu and Boris Gänsicke argue the evidence fits a scenario where a Pluto-like world—icy, nitrogen-rich, perhaps once on a stable orbit—veered too close to the white dwarf, was pulled apart by tidal forces, and gradually accreted onto the star’s surface. “The white dwarf likely accreted fragments from the crust and mantle of a Pluto-like icy world,” Sahu said.
What’s startling is not just that the white dwarf is eating material, but what it is eating. Most previous cases involved rocky or metallic debris—asteroids, the remnants of terrestrial planets. Here, the diet is icy and volatile. The researchers deduced that the material falling in has a rate equivalent to the mass of a large whale every second, sustained for at least 13 years.
A key clue in the detection was nitrogen abundance. Typical comets have some nitrogen, but not to the extreme levels seen here. Nitrogen ice is characteristic of Pluto, whose surface is coated in frozen nitrogen, methane, and carbon monoxide. Because of that signature, researchers believe this is not a comet, but something resembling a dwarf planet. “If not an entire Pluto, it would be a fragment chipped off a Pluto-like world,” Gänsicke noted.
The white dwarf in question has a mass about 57 percent that of our Sun. Though it is compact—roughly Earth’s size in diameter—its gravity is intense. When something ventures close enough, it can be torn apart and gradually spiral inward. Over time, these accreted materials leave telltale chemical fingerprints in the white dwarf’s outer layers, which astronomers can detect using spectrographs.
Why does this matter? First, it deepens our understanding of planetary systems’ long game. Planets, moons, and icy bodies may persist far beyond the lifetime of their parent stars—or suffer catastrophic ends. Witnessing one being shredded reveals how “dead” systems continue to evolve. Second, it tells us icy bodies may be more common in alien systems than we suspected—a clue in the search for water and habitability in other systems. Third, it challenges our assumptions: when a star dies, its leftovers don’t just sit inert—they can keep interacting with their surroundings in dramatic ways.
From Earth, the find feels like watching a crime scene in slow motion across cosmic distances. What once may have been a distant, icy orb drifting peacefully is now torn apart, its material drawn inexorably inward. For observers, there’s a sense of poignancy—a reminder that in the universe, nothing is static, and that even after death, stars continue to shape and consume their neighborhoods.
As we refine telescopes, instruments, and spectroscopic techniques, more such events may come to light. Each one will carry its own tale of destruction, survival, and transformation in the cold reaches of space. For now, this white dwarf’s banquet offers both a grim spectacle and a profound insight into how worlds end—and what they leave behind.
Source: Reuters
