A planetary destruction event has been detected in the Helix Nebula (NGC 7293), located 650 light-years from Earth in the constellation Aquarius. New observations from NASA’s Chandra X-ray Observatory suggest that a white dwarf, WD 2226-210, has torn apart a nearby planet, producing an unusual X-ray signal that astronomers have monitored for over four decades.
Scientists analyzing data from Chandra, along with observations from the XMM-Newton telescope, propose that material from a planet in close orbit around WD 2226-210 is being pulled onto the white dwarf’s surface. This event provides strong evidence of planetary destruction by a dying star, a phenomenon never observed before within a planetary nebula.
“We think this X-ray signal could be from planetary debris pulled onto the white dwarf, as the death knell from a planet that was destroyed by the white dwarf in the Helix Nebula. We might have finally found the cause of a mystery that’s lasted over 40 years,” Sandino Estrada-Dorado of the National Autonomous University of Mexico, the study’s lead author, stated.
Discovery of X-ray emission
Multiple X-ray observatories since 1980, including the Einstein Observatory and ROSAT, have detected strong X-ray emissions from WD 2226-210, an unusual occurrence for white dwarfs, which normally do not emit high-energy X-rays. The X-ray readings remained constant over time, but their origin remained unexplained.
Observations by Chandra and XMM-Newton between 1992 and 2002 confirmed the presence of X-rays and revealed subtle periodic variations in brightness approximately every 2.9 hours. The fluctuations suggested that debris from a destroyed planet was extremely close to the white dwarf and being gradually accreted onto its surface.
“The mysterious signal we’ve been seeing could be caused by the debris from the shattered planet falling onto the white dwarf’s surface, and being heated to glow in X-rays,” Martin Guerrero of the Institute of Astrophysics of Andalusia in Spain said.
Destroyed planet
Prior studies identified a Neptune-sized planet orbiting WD 2226-210 at a close distance, completing one orbit in under three days. The new research suggests that an even larger planet, possibly Jupiter-sized, once existed even closer to the star but was gradually pulled in because of gravitational interactions with other planets in the system.
Once the planet reached a main distance, the intense tidal forces of the white dwarf ripped it apart, sending fragments into orbit around the star. Over time, this debris formed an accretion disk, with material gradually falling onto the white dwarf’s surface and producing the persistent X-ray emissions detected by astronomers.
“It’s important to find more of these systems because they can teach us about the survival or destruction of planets around stars like the Sun as they enter old age,” Diego Alejandro Vasquez-Torres of the National Autonomous University of Mexico noted.
Observations of Helix Nebula
The Helix Nebula, also known as NGC 7293, is one of the closest and most well-studied planetary nebulas. It formed when a Sun-like star expelled its outer layers, leaving behind a hot white dwarf at its core.
The composite image of the nebula used in this study combines X-ray data from Chandra (magenta), optical data from Hubble (orange, light blue), infrared data from ESO’s VISTA telescope (gold, dark blue), and ultraviolet data from GALEX (purple).
The labeled image of the nebula shows WD 2226-210 at its center, surrounded by the remnants of the planet it likely destroyed. An artist’s impression illustrates how the planet was torn apart, with debris forming a glowing arc around the white dwarf. The gravitational interactions responsible for pulling the planet inward may have involved other planets still present in the system, as indicated by additional planetary bodies depicted in the illustration.
Class of X-ray sources
The findings from WD 2226-210 suggest that this system may belong to a previously unknown class of X-ray-emitting white dwarfs. While some white dwarfs are known to pull material from companion stars, WD 2226-210 appears to be consuming debris from a disrupted planet. This mechanism could explain similar X-ray behavior observed in two other white dwarfs, which may also be accreting planetary material.
Two other white dwarfs, G29-38 and KPD 0005+5106, exhibit similar X-ray behavior and may also be accreting planetary material. G29-38 is known for its infrared excess, indicating the presence of a dusty debris disk formed from a disrupted planetary body. Observations suggest that it is actively accreting material from this debris, leading to detectable X-ray emissions.
KPD 0005+5106, an extremely hot white dwarf, shows variable X-ray emission, which researchers believe could result from an accretion of planetary material, either from a planetary companion or remnants of a destroyed planet.
“These three white dwarfs may constitute a new class of variable, or changing, object,” Co-author Jesús Toala of the National Autonomous University of Mexico remarked.
References:
1 X-ray Signal Points to Destroyed Planet, Chandra Finds – CHANDRA X-RAY OBSERVATORY – March 4, 2025
2 Accretion onto WD 2226-210, the central star of the Helix Nebula – S Estrada-Dorado, M A Guerrero, J A Toalá, et. al., – Monthly Notices – December 12, 2024 – – OPEN ACCESS
Rishika holds a Master’s in International Studies from Stella Maris College, Chennai, India, where she earned a gold medal, and an MCA from the University of Mysore, Karnataka, India. Previously, she served as a Research Assistant at the National Institute of Advanced Studies, Indian Institute of Science, Bengaluru, India. During her tenure, she contributed as a Junior Writer for Europe Monitor on the Global Politics website and as an Assistant Editor for The World This Week. Her work has also been published in The Hindu newspaper, showing her expertise in global affairs. Rishika is also a recipient of the Women Empowerment Award at the district level in Haryana, India, in 2022.