Science Reporting

First eruption detected in a star 450 light-years away

A powerful star eruption has been identified in the atmosphere of the active star HR 9024, also known as OU Andromedae, a giant star with a high X-ray brightness that causes a giant plasma bubble around the surface of the star itself. The star is about 450 light-years away from us.

This is the first direct observation of a coronal mass ejection (CME), a phenomenon that until now had only been observed directly on our sun. During this blasting, very hot material was ejected with a speed of between 362,000 and one and a half million miles per hour.

The study, published in Nature Astronomy, describes how the astronomers of the National Institute of Astrophysics in Italy have collected and analyzed the data of the Chandra X-ray Observatory, a NASA space telescope.

Explaining the mode of data analysis is the researcher Costanza Argiroffi of the University of Palermo: “The technique we used is based on monitoring the speed of plasma during a stellar blast. This is because, in analogy with the solar case, it is expected that, during a blast, the plasmas confined in the coronal arc where the blast occurs move first upwards, and then towards the lower layers of the stellar atmosphere. In addition, it is also expected to observe a further motion, always directed upwards, due to the CME associated with the blasting.”

The study is important because it shows for the first time that coronal mass ejections can be considered as common events also in other stars, at least in those magnetically active. Moreover, the data confirm the previous theories related to this type of stellar phenomenon.