New Method Estimates Magnetic Field of Distant Exoplanet

A new method has been developed by scientists that allows them to estimate the magnetic field of a distant exoplanet that is a planet positioned outside the solar system and which orbits a different star.

Scientists were able to estimate the value of the magnetic moment of the planet HD 209458b. The group of scientists and one of the researchers of the Lomonosov Moscow State University (Russia) published their article in Science magazine.

In the last 20 years, which passed since the discovery of the first planet outside the solar system, astronomers have progressed a lot to study these objects. One of the vital properties of solid and gaseous planets is their possible magnetic field and its magnitude.

On Earth, it protects all the living creatures from hazardous cosmic rays and also aid animals to navigate in space. The value of the magnetic moment and the shape of the magnetosphere of the exoplanet HD 209458b was estimated by the Kristina Kislyakova of the Space Research Institute of the Austrian Academy of Sciences in Graz with an international group of physicists for the first time ever.

In order to know more, scientists utilized observations by HD 209458b in the hydrogen Lyman-alpha line at the time of transit, the Hubble Space Telescope. Firstly, the scientists examined absorption of the star radiation by the atmosphere of the planet. After, scientists estimated the shape of the gas cloud surrounding the hot Jupiter, and the configuration of the magnetosphere.

"We modeled the formation of the cloud of hot hydrogen around the planet and showed that only one configuration, which corresponds to specific values of the magnetic moment and the parameters of the stellar wind, allowed us to reproduce the observations", explained Kristina Kislyakova. There is possibility that this new developed method could be used for every planet, including Earth-like planets.