Scientists have been using the Low Frequency Array (LOFAR) radio telescope to study unusual radio waves that are being transmitted from a nearby red dwarf star called GJ1151. Scientists say that the radio waves have the signature of an aurora that is caused by the interaction between a star and its planet. The team notes that such a radio wave has been predicted for over three decades, but this is the first time the signature and been detected.
Scientists studying the data gathered say that the door is open for a new way of discovering exoplanets in the habitable zone of a parent star. Red dwarfs are the most abundant sort of stars in the galaxy and are smaller and cooler than the Sun. A planet could be much closer to the star than the Earth is and still be in the habitable zone.
A red dwarf has a much stronger magnetic field than our Sun and would subject a planet in its habitable zone to intense magnetic activity. Such activity can heat the planet and erode its atmosphere. The radio emission that is associated with the process is one of the few tools that scientists have to measure the effect.
The magnetic field would power aurorae and the radio emission of the star. Our Sun has a much weaker magnetic field and a larger distance to the planets meaning that similar currents aren’t generated in the solar system. In our solar system, Jupiter and its moon Io do generate similar bright radio emissions that can outshine the Sun at “sufficiently low frequencies.”
Since the team was familiar with the interaction of Jupiter and Io, they were able to adapt knowledge of decades of radio observations of Jupiter to GJ1151 and its planet. The team is now concentrating on finding similar emissions from other stars.