2024-08-09 04:00:13
An intriguing phenomenon surrounds the rotation of V889 Herculis, a star similar to our Sun but also so very different. Located about 115 light-years away, this star defies established stellar models by rotating faster at a latitude of about 40 degrees, unlike our Sun which reaches its vitesse maximum at the equator.
Crédit: Jani Närhi, University of Helsinki
Researchers at the University of Helsinki discovered this atypical rotation by applying an innovative statistical technique to data known. The anomalies detected suggest that our understanding of the dynamic stellar and magnetic dynamos is incomplete.
Mikko Tuomiwho coordinated the study, emphasizes that this discovery is crucial to better understand the physique stars, especially to predict phenomena ofactivity on the surface solar, such as spots and flares.
Stars, spheres of dynamic plasma, do not have solid surfaces. Their differential rotation is caused by plasma convection, affecting the rotation rate at different latitudes. However, factors such as stellar mass, age, chemical composition, rotation period and the magnetic field also influence this phenomenon.
The team also studied a second star, LQ Hydrae, which showed a more uniform rotation. These results were obtained thanks to long-term observations at Fairborn Observatory, led by senior astronomer Gregory Henry, which tracked variations in brightness over several decades.
The target stars, V889 Herculis and LQ Hydrae, are very young at about 50 million years old and rotate rapidly, with rotation periods of about one and a half days. These observations provide detailed rotational cycles, essential for understanding the physics of young and active stars.
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#star #rotates #quickly #equator
