Mystery of Exoplanet's Magnetic Field Unlocked

Scientists using the Hubble Space Telescope were thrilled to catch a view of the Jupiter-sized exoplanet HD 209454b as it passed across the face of its parent star, relative to the observatory’s line of sight.

But what they found left them puzzled: a strange, asymmetrical pattern of highly charged hydrogen atoms moving quickly away from the star.

With the help of a new three-dimensional computer model, they now have an explanation. The model, which takes into account all known interactions between stellar winds and planetary atmospheres, indicates that the mysterious hydrogen flow is a telltale sign of the planet being bathed in stellar winds from its parent star that reached 249 mile-per-second during the transit.

The model also shows that the planet’s magnetic field was about 10 percent as powerful as Jupiter’s at the time.

The new model, reported in this week’s Science, is expected to become a useful tool for assessing how planets beyond the solar system are interacting with their host stars.

From Discovery News