Some young stars in the Milky Way just cannot stop bedevilling scientists with their erratic behaviours and FU Orionis, a binary star system, which has been erupting violently since 1936, is one such glaring example, reported Science Alert Tuesday.

According to the findings published in the Astrophysical Journal, the binary star system suddenly sparked flares 1,000 times its usual brightness, leaving experts to scratch their heads.

Such behaviour had not been in such a young star — 2 million years old — earlier, but now scientists have answered.

“FU Ori has been devouring material for almost 100 years to keep its eruption going. We have finally found an answer to how these young out-bursting stars replenish their mass,” Antonio Hales of the National Radio Astronomy Observatory said.

“For the first time we have direct observational evidence of the material fueling the eruptions.”

Scientists in their findings suggested that the material is composed of carbon monoxide in the system but it’s not enough to increase the luminosity, therefore there must be other material that it ate over time.

“It is possible that the interaction with a bigger stream of gas in the past caused the system to become unstable and trigger the brightness increase,” Hales noted.

“We have been studying FU Orionis since ALMA’s first observations in 2012,” Hales noted, adding that “it’s fascinating to finally have answers.”