(ORDO NEWS) — Researchers have identified for the first time signs of a magnetic field surrounding a planet outside the solar system. The Earth’s magnetic field acts as a shield deflecting high-energy particles known as the solar wind. Magnetic fields can play a similar role on other planets.
An international team of astronomers used data collected by the Hubble Space Telescope to detect signs of a magnetic field on a planet outside our solar system. These findings became the first case of detection of a magnetic field around an exoplanet.
The magnetic field is best suited to explain the observation of a vast region of space filled with charged carbon particles that surrounds the planet and trails behind it in a long “tail”. Magnetic fields play an important role in protecting planetary atmospheres, so the ability to detect the magnetic fields of exoplanets is an important step towards a deeper understanding of these planets.
The team used Hubble to observe the six-fold transit of planet HAT-P-11b, the size of Neptune, about 123 light-years from Earth. The observations were carried out in the ultraviolet range.
The physics of the magnetosphere of the planet HAT-P-11b is similar to the physics of the Earth’s magnetic shell, however, the proximity of the exoplanet to the parent star – the planet lies at a distance of about 1/20 of an astronomical unit (1 AU is equal to the average distance from the Earth to the Sun) from the star – causes heating of the upper layers of the atmosphere and its “boiling away” into space, as a result of which a magnetic tail is formed.
The researchers also found that the metallicity of the planet HAT-P-11b’s atmosphere was actually lower than expected. In the solar system, the ice gas giants, Uranus and Neputnus, are richer in metals (elements heavier than hydrogen and helium), but have weaker magnetic fields, while the larger gas giants, Jupiter and Saturn, have lower metallicities and stronger magnetic fields… The low metallicity of the planet HAT-P-11b’s atmosphere is challenging current models of exoplanet formation, researchers say.
Thus, although the mass of the planet HAT-P-11b is only 8 percent of the mass of Jupiter, in reality this exoplanet resembles a mini-version of Jupiter more closely than Neptune, the authors say.
The work was published in the journal Nature Astronomy; lead author Lotfi Ben-Jaffel of the Astrophysical Institute in Paris, France.
Contact us: [email protected]