Astronomers Discover White Dwarf Devouring Pluto-Like Object

A team of astronomers has made a striking discovery, observing a white dwarf star consuming material from a Pluto-like object. Using the Hubble Space Telescope, researchers identified WD 1647+375 as the star in question, which has been actively devouring the remnants of an icy planetesimal. This finding was detailed in a paper published on September 18, 2023, in the Monthly Notices of the Royal Astronomical Society.

The research indicates that the white dwarf’s intense gravitational forces likely captured the fragment from its original orbit, suggesting that it was once a part of a larger icy body similar to those found in our own Kuiper Belt. Analysis of the material revealed a chemical composition rich in carbon, sulfur, nitrogen, and oxygen, hinting that the planetesimal may have contained water before its consumption.

Understanding the Cosmic Meal

Typically, the atmosphere of a white dwarf is composed mainly of hydrogen and helium. However, WD 1647+375 displayed an unusual presence of volatiles, which are chemical substances with low melting points. This anomaly prompted the research team to investigate further. According to study lead author Snehalata Sahu, “White dwarfs act like cosmic crime scenes. When a planetesimal falls in, its elements leave chemical fingerprints in the star’s atmosphere, letting us reconstruct the identity of the ‘victim.’”

The findings highlighted a particularly high concentration of nitrogen in the dwarf’s atmosphere. This element serves as a crucial indicator of icy worlds, reinforcing the idea that the consumed object was not rocky, but rather composed of ice. Sahu noted, “We know that Pluto’s surface is covered with nitrogen ices. We think that the white dwarf accreted fragments of the crust and mantle of a dwarf planet.”

The research team estimated that WD 1647+375 has been feeding on this icy object for at least the past 13 years, consuming material at an astonishing rate of around 440,925 pounds (200,000 kilograms) per second. The original object is believed to have had a diameter of at least 3 miles (5 kilometers).

Implications for Cosmic Systems

This remarkable discovery not only sheds light on the processes surrounding white dwarfs but also offers insights into the broader context of cosmic systems. The study suggests that icy planetesimals, such as the one consumed by WD 1647+375, play a crucial role in delivering essential volatiles—like water—to terrestrial planets in other solar systems. This delivery is considered vital for the potential development of life beyond Earth.

Researchers believe that with the confirmation of such icy bodies existing in space, further studies can be conducted on other similar objects. Notably, the recent interstellar visitor, 3I/ATLAS, may provide additional opportunities for exploration.

Looking ahead, Sahu emphasized that the fate of our own solar system could mirror the cosmic events witnessed around WD 1647+375. As our Sun eventually exhausts its fuel and transitions into a white dwarf, the planets in our solar system may face a similar fate as the icy planetesimal. “If an alien observer looks into our solar system in the far future,” Sahu remarked, “they might see the same kind of remains we see today around this white dwarf.”

This discovery not only deepens our understanding of stellar evolution but also serves as a reminder of the dynamic and often brutal processes at play in the universe.