Astronomers are using the Orion Nebula as a time machine to look back at what our own sun might have been like, early in its history. Looking at the Orion Nebula, they find x-rays streaming onto an otherwise cold and quiet disc around a newly forming star.

Eric Feigelson is an astronomer at Penn State University.

He used the orbiting Chandra X-ray Observatory to peer at the Orion Nebula – a vast cloud of gas and dust 1,600 light-years away – where new stars are forming. He found large and frequent bursts of x-rays from these new stars.

Eric Feigelson: Our sun today is flaring as we speak, but at a very low level – maybe one millionth of its energy is emitted in x-rays. And these flares are like magnetic short-circuits on the surface of the sun, where the magnetic fields get tangled, and sort of spark and heat up gas to millions of degrees. What is new and remarkable is that by looking at the Orion Nebula cluster of young stars, we found that the stars, and by inference, the young sun, emitted far stronger flares, far more often than it does today.

Feigelson believes these bursts of x-rays from young stars might protect any possible planets forming in their vicinity. It’s thought that, as new planets form in the disks around young stars, their tendency is to spiral inward – and be lost. The x-rays shining on the disc might make the disc turbulent – suppressing this migration of planets.

Eric Feigelson: And so, we almost might think of the x-rays as a planetary protection program.

Thanks today to Research Corporation – a foundation for the advancement of science.

Our thanks to:
Eric Feigelson
Penn State University