Astronomers Detect Magnetic Fields on Seven Hot Jupiters

Astronomers have obtained the strongest evidence to date that planets beyond our solar system possess magnetic fields, a discovery that significantly advances the understanding of these distant worlds. The finding, published in the journal Nature Astronomy, is based on observations of wind patterns on seven large, hot gas exoplanets known as "ultrahot Jupiters."

The international research team, led by astronomer Julia Seidel of France's Observatoire de la Côte d'Azur, initially set out to measure wind speeds on these extreme planets. Using data from the European Southern Observatory's Very Large Telescope in Chile and the Gemini North telescope in Hawaii, they analyzed the atmospheres of seven gas giants orbiting very close to their host stars. These planets are tidally locked, meaning one side permanently faces the star, resulting in scorching dayside temperatures and freezing nightsides. This extreme temperature difference drives powerful winds, which the team measured at speeds ranging from approximately 7,200 to 25,000 kilometers per hour.

However, the researchers observed a counterintuitive pattern: the hotter the planet, the slower the wind. This finding contradicted...