First evidence of a magnetic field produced by an exoplanet, with the help of Hubble. When is the first detection around an exoterre?
Oneis a parameter important defining the evolution and habitability of a planetary environment. For example, protect our of the’ and thus preserves life on its surface. All the bodies of the do not have intrinsic magnetospheres, while their presence on , although examined with observations of radio, has so far escaped detection.
Using the observations of the, a new study published in reports the first unambiguous detection of a magnetosphere for , a gaseous planet of type discovered in 2008 (123 of the Solar System).
How to detect the magnetic field of a distant planet?
The detection and characterization of the planetary magnetic field is carried out by tracking the atoms ofionized formed in the planet’s atmosphere. When these escape from the atmosphere, they are captured by the magnetic field, and their detection at great distances from the planet traces the properties of the magnetic field.
To accomplish this task, the international research team simulated in detail the physical and chemical formation and evolution of these ions from the deep atmosphere to the extended environment between the exoplanet and itshost using a combination of advanced models developed in France (IAP, CEA, GSMA) and internationally. The observations were obtained thanks to the HST / PanCET research program dedicated to the characterization of .
Models of exoplanet formation may be inaccurate
Analysis of Hubble’s measurements also suggests that the exoplanet has amuch lower (a measure of the number of atoms heavier than the present in the planet) than predicted by theoretical models, in agreement with other independent studies. This result is significant, as it adds credit to the conclusion that HAT-P-11b (26.7 times the mass of Earth) probably really has lower metallicity than expected. This means that the may be inaccurate, suggesting that more work needs to be done to refine current theories on the formation and evolution of some exoplanets.
By measuring atmospheric metallicity and simultaneously detecting the planetary magnetic field, this study also provides – for the first time – a bridge between two subjects of planetary science that are generally not connected: the physics of the interior of the planets. and thespace (the study of a planetary magnetosphere).