There is a young star that for the last eight decades has been gobbling up the disk of gas and dust that surrounds it.
The object, called FU Orionis, is a variable star that in the 1930s suddenly became 100 times brighter. The increase in luminosity was due to a three-month binge of gas, which led the star to heat up the interior of the disk to 7,000 Kelvin (12,000°F / 6,700°C).
The event was the most powerful ever seen in a Sun-like star, and astronomers believe it might have implications for how planetary systems like ours form.
"By studying FU Orionis, we're seeing the absolute baby years of a solar system," Joel Green, a project scientist at the Space Telescope Science Institute in Baltimore, Maryland, said in a statement. "Our own sun may have gone through a similar brightening, which would have been a crucial step in the formation of Earth and other planets in our Solar System."
Green and his team used both recent observations from the airplane observatory SOFIA and data from 2004 collected by NASA’s Spitzer Space Telescope. Combining the two allowed the researchers to study if and how the star's behavior has changed over the years.
In the last 12 years, there has been a 13 percent decrease in infrared light at shorter wavelengths but not at longer wavelengths, an indication that the star has been scooping up the hottest and closest material around.
"A decrease in the hottest gas means that the star is eating the innermost part of the disk, but the rest of the disk has essentially not changed in the last 12 years," Green said. "This result is consistent with computer models, but for the first time we are able to confirm the theory with observations."
Green has presented these results at the American Astronomical Meeting in San Diego this week. He and his team also compared the recent observation with historical data, and estimated that FU Orionis has eaten the equivalent of 18 Jupiters in the last 80 years.
The feeding frenzy is expected to last for another few hundred years, with the researchers convinced that it will have a profound effect on the protoplanetary disk surrounding FU Orionis. If the Sun had undergone such a phase, it could explain the different chemistry between Earth and Mars.
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