It's Always a Windy Day Around This Baby Star

T Tauri stars are young stars not so dissimilar to what our sun would have looked like when it was an infant, approximately 4.5 billion years ago. These stellar objects are often easy to identify as they emit a very specific type of radiation, but some T Tauris buck the trend and generate a very strange signature of infrared light.

Now, astronomers using the powerful Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama Desert, Chile, think they’ve worked out why some of these T Tauris are oddballs — they have some pretty wild space weather.

“The material in the disk of a T Tauri star usually, but not always, emits infrared radiation with a predictable energy distribution,” said astronomer Colette Salyk, of the National Optical Astronomical Observatory (NOAO) in Tucson, Ariz. “Some T Tauri stars, however, like to act up by emitting infrared radiation in unexpected ways.”

Like our young sun, T Tauris are enshrouded in a dusty protoplanetary disk and are not visible in optical light. ALMA can cut through the dust and analyze the properties of the radiation they produce.

While studying AS 205 N, a T Tauri star located 407 light-years from Earth in a star-forming region in the constellation Ophiuchus, Salyk’s team discovered what may be causing the anomalous infrared signal that some T Tauri’s generate. ALMA was used to track the distribution of carbon monoxide gas, which is easily identifiable by ALMA and can be used as a tracer for the gas and dust blowing from the star in a stellar wind.

After careful analysis, the astronomers found that AS 205 N’s strange signal is probably being caused by its binary star partner, AS 205 S, which is itself a binary star. This multi-star configuration appears to be pulling material from AS 205 N, producing a powerful stellar wind where material is being dragged from its surface rather than being blown away by the young star.

Read more at Discovery News