10/12/2021 at 1:49 PM CEST
A new astronomical study carried out at the University of Queensland, in Australia, has used the most powerful radio antenna in the world to discover distant stars that would “hide” hidden stars orbiting around them, according to the strange radio signals they emit. The researchers used the LOFAR low-frequency radio telescope, located in the Netherlands.
The planets of the Solar System emit strong radio waves when their magnetic fields interact with the solar wind, which have already been detected and analyzed by astronomers in multiple previous studies. But radio signals from planets outside our Solar System are much more difficult to detect.
Taking advantage of technological advantages
The radio astronomy It offers numerous advantages over other techniques to achieve this objective, even more so if advanced instruments such as the LOFAR radio telescope are used. Previously, it was only possible to detect the closest stars that generated a constant radio emission. The new radio telescopes make it possible to identify signals from farther stars, and at the same time check if there are planets that orbit those stars.
In this case, the specialists focused on the stars red dwarfs, which are smaller than the Sun and have intense magnetic activity, which can lead to radio emissions. In addition to discovering almost twenty new stars, they recorded other phenomena that could lead to the identification of new exoplanets.
According to a press release, some of the radio signals detected come from the magnetic connection of stars and planets in orbit that have not yet been observed, in a phenomenon similar to the interaction between Jupiter and its moon, Io. Scientists identified this strange mechanism in 4 of the identified stars, according to the study published recently in the journal Nature Astronomy.
It’s known that Io, a satellite with strong volcanic activity, generates eruptions that emit material more than 300 kilometers high: its low gravity allows part of this material to be expelled from the surface, depositing in a ring that covers its orbit. Such material can be ionized, being trapped in Jupiter’s intense magnetic field.
Related topic: A colossal cosmic jellyfish emits strange radio signals.
Auroras and radio signals
The researchers believe that a similar phenomenon marks the dynamics of the new discovered systems: that is why they emit radio signals, generated from the auroras produced by magnetic interactions. Even on Earth, the interaction of our planet’s magnetic field with the solar wind generates bright auroras that emit powerful radio waves, as well as being fantastic visual spectacles.
For Australian astronomers, some of the stars discovered in deep space harbor “Enlarged versions” of Jupiter and Io: they present a planet wrapped in the magnetic field of a star, emitting material in vast currents that later produce powerful auroras, which finally generate radio signals.
Finally, the scientists concluded that the Square Kilometer Array radio telescope, developed by Australia and South Africa and which would be operational in 2029, will allow us to verify the presence of these planets and also try to discover other stars at much greater distances.
The population of M dwarfs observed at low radio frequencies. Callingham, JR, Vedantham, HK, Shimwell, TW et al. Nature Astronomy (2021) .DOI: https: //doi.org/10.1038/s41550-021-01483-0
Photo: A new research discovered distant stars that could host new planets, from radio emissions apparently produced by strong auroras, more powerful than those recorded on Earth when the Earth’s magnetic field interacts with the solar wind. These would be systems with intense magnetic interactions, such as those recorded between Jupiter and its moon Io. Credit: Yuri_B on Pixabay.