NASA | JPL-Caltech | Spitzer Space Telescope | 2016 Jun 14
In 1936, the young star FU Orionis began gobbling material from its surrounding disk of gas and dust with a sudden voraciousness. During a three-month binge, as matter turned into energy, the star became 100 times brighter, heating the disk around it to temperatures of up to 12,000 degrees Fahrenheit (7,000 Kelvin). FU Orionis is still devouring gas to this day, although not as quickly.
This brightening is the most extreme event of its kind that has been confirmed around a star the size of the sun, and may have implications for how stars and planets form. The intense baking of the star's surrounding disk likely changed its chemistry, permanently altering material that could one day turn into planets. ...
Visible light observations of FU Orionis, which is about 1,500 light-years away from Earth in the constellation Orion, have shown astronomers that the star's extreme brightness began slowly fading after its initial 1936 burst. But Green and colleagues wanted to know more about the relationship between the star and surrounding disk. Is the star still gorging on it? Is its composition changing? When will the star's brightness return to pre-outburst levels?
To answer these questions, scientists needed to observe the star’s brightness at infrared wavelengths, which are longer than the human eye can see and provide temperature measurements. ...
