A star system 160,000 light-years from the Earth has two stars orbiting so closely, they're in contact and exchanging material in what could end up being a "kiss of death," astrophysicists say.

Detected by the European Southern Observatory's (ESO) Very Large Telescope in Chile, the two bodies making up the VFTS 352 star system are so close to each other that a bridge of material has formed between them, they say.

"The VFTS 352 is the best case yet found for a hot and massive double star that may show this kind of internal mixing," says Leonardo A. Almeida at the University of Sao Paulo in Brazil. "As such it's a fascinating and important discovery."

The hot, bright, massive and young pair of stars orbit each other in little more than a day, and their centers are only 7.5 million miles apart, constituting what scientists call an "overcontact binary."

Since both of the stars are around the same size, material is likely not being sucked from one into the other but rather is being shared, with about 30 percent of their combined materials being held in the bridge between them, the researchers say.

Such overcontact binaries are rare and difficult to catch in the act, they explain, because binary stars are only in this phase for a short time.

The outcome of such a phase is likely one of two possibilities, both cataclysmic, study leaders explain in a paper appearing in The Astrophysical Journal.

They may merge to create a rapidly spinning, gigantic magnetic star, says project lead scientist Hugues Sana from the University of Leuven in Belgium.

"If it keeps spinning rapidly it might end its life in one of the most energetic explosions in the Universe, known as a long-duration gamma-ray burst," he says.

If the stars manage to avoid merging, the result could be something not predicted by classic stellar evolution assumptions, says theoretical astrophysicist Selma de Mink from the University of Amsterdam.

"In the case of VFTS 352, the components would likely end their lives in supernova explosions, forming a close binary system of black holes," she suggests. "Such a remarkable object would be an intense source of gravitational waves."

The researchers say confirming the reality of such a result is something that would be considered a breakthrough in stellar astrophysics.

Paired star systems like VFTS 352 play a crucial role in the creation of galaxies, the researchers note, and are thought to be significant producers of heavier elements such as oxygen.