February 13, 2017

Hubble spots white dwarf star ripping up Halley’s Comet’s big brother

Researchers using NASA’s Hubble Space Telescope have observed, for the first time ever, an enormous object with the composition of a comet being shredded and scattered by a white dwarf, the burned-out husk of a massive star.

Researchers said the comet-like object has a chemical makeup comparable to that Halley’s Comet, but it is 100,000 times bigger and has a much greater quantity of water. The object was also determined to be rich in the elements crucial for life, including carbon, oxygen, and nitrogen.

These observations are evidence for the existence of belt of comet-like objects orbiting the white dwarf, comparable to the Kuiper Belt that encircles the Sun at the outer reaches of our solar system. These icy bodies seemingly survived the star’s progression from being a swollen red giant to a collapsed, dense white dwarf.

Roughly 25 to 50 percent of white dwarfs are acknowledged to be dirtied with debris from rocky, asteroid-like bodies, however, this is the first time an object created from icy, comet-like material has been seen slipping into a white dwarf’s atmosphere.

Discovering Hidden Planets

The outcomes also suggest the existence of hidden planets which may have affected the belt and acted as a “bucket brigade” to attract the icy bodies into the white dwarf. The diminished star also has a partner star, which may cause objects from the belt to move in the direction of the white dwarf.

The research team that made the discovery said their observation was the first time nitrogen was found in the debris that dropped onto a white dwarf.

“Nitrogen is a very important element for life as we know it,” team member Siyi Xu of the European Southern Observatory, said in a news release. “This particular object is quite rich in nitrogen, more so than any object observed in our solar system.”

The Kuiper Belt, which stretches outward from Neptune’s orbit, is home to numerous dwarf planets, comets, and other small objects left over from the creation of the solar system. Incidentally, scientists have said comets from the Kuiper Belt may have sent water and other building blocks of life to Earth billions of years ago.

The new findings support the notion that belts of icy bodies are also in other planetary systems, and have persisted throughout their star’s development.


Image credit: NASA, ESA, and Z. Levy (STScI)