Radio waves from a nearby star could help scientists discover new habitable planets

Aoife O'Brien

Astronomers have discovered unusual radio waves coming from a nearby star according to a paper which was co-authored by DCU’s Dr Shane O’Sullivan from the School of Physical Sciences and the Centre for Astrophysics and Relativity.

The discovery was made using the Low Frequency Array (LOFAR) radio telescope which combines signals from more than 100,000 individual radio antenna dipoles. This unparalleled astronomical data collection forms a ‘dish’ of 1900 kilometres in diameter and spans seven European countries.

The unusual radio waves detected by the LOFAR radio telescope are produced by aurorae caused by the interaction between the magnetic field of this star and an exoplanet beyond our solar system.

The star, a red dwarf called GJ1151, is located in the Ursa Major constellation and is almost 25 light years from Earth according to the paper published in Nature Astronomy.

This is the first time astronomers have seen these types of radio waves from a star-planet interaction.

Dr. Harish Vedantham, the lead author of the study at the Netherlands Institute for Radio Astronomy (ASTRON) said “Our work has put us on an intriguing path by demonstrating that LOFAR is sensitive enough to detect the long-predicted radio waves from a star-planet interaction.

This discovery provides a new opportunity to discover exoplanets in the habitable zone and to study the environment they exist in.

The red dwarf star GJ1151 which was discovered to be emitting these unusual radio waves is a class of stars smaller and cooler than the Sun but with intense magnetic fields

Red dwarfs are the most abundant type of star in our Milky Way and are likely to host potentially habitable planets.

However, such planets will have to orbit much closer to the star compared to the distance between the Sun and the Earth and will be strongly affected by the intense stellar magnetic field.

This magnetic interaction can heat and even erode the exoplanet’s atmosphere.

According to Dr. Vedantham radio observations are one of the few tools available to study the magnitude of this effect.

“We want to use future radio observations to figure out how detrimental this interaction is to exoplanets and what it means for habitability.”

Dr. Shane Sullivan said, “This is an exciting time for radio astronomy, as the LOFAR Two-metre Sky Survey (LoTSS) is providing the opportunity for many new discoveries such as this one.

DCU is part of a consortium running the I-LOFAR station located in Birr, Co. Offaly and the Irish station forms part of the International LOFAR Telescope that made the observations.”

Aoife O’Brien

Image Credit: Pixrepo