Windy conditions around infant star?

Astronomers have observed what may be the first-ever signs of windy weather around an infant analogue - called T Tauri - of our Sun.

Some 4.5 billion years ago, the Sun was also an infant star.

This discovery may help explain why some T Tauri stars have disks that glow weirdly in infrared light while others shine in a more expected fashion.

They are relatively normal, medium-size stars that are surrounded by the raw materials to build both rocky and gaseous planets.

Though nearly invisible in optical light, these disks shine in both infrared and millimetre-wavelength light.

"The material in the disk of a T Tauri star usually, but not always, emits infrared radiation with a predictable energy distribution," said Colette Salyk, an astronomer with the National Optical Astronomical Observatory (NOAO) in Arizona.

Using the Atacama Large Millimeter/submillimeter Array (ALMA), Salyk and her colleagues looked for evidence of a possible wind in AS 205 N - a T Tauri star located 407 light-years away at the edge of a star-forming region in the constellation Ophiuchus.

The researchers were able to study the distribution of carbon monoxide around the star.

Carbon monoxide is an excellent tracer for the molecular gas that makes up stars and their planet-forming disks.

These studies confirmed that there was indeed gas leaving the disk's surface, as would be expected if a wind were present.

"We hope these new ALMA observations help us better understand winds, but they have also left us with a new mystery. Are we seeing winds or interactions with companion star?" asked Salyk.

The paper was published in the Astrophysical Journal.