Radio stars and exoplanets: exploiting a new low-frequency window onto exoplanet habitability

Summary

While identifying planets around stars other than our Sun has become standard in astronomy, assessing the potentially habitability of such exoplanets has remained elusive. A low-frequency radio detection of a stellar system is a powerful tool for assessing the environmental conditions around a star. However, all previous searches have lacked the sensitivity to detect any such emission.

Recently, I achieved the very first radio detection of a quiescent stellar system in my highly-sensitive survey of nearby stars using the Dutch radio telescope LOFAR. The characteristics of the emission, and available optical data, suggest such emission is likely coming from a star-exoplanet interaction or from a stellar corona with properties that violate our best theoretical models. Both conclusions have high-impact ramifications for understanding the space weather experienced by exoplanets.

This first detection merely represents the tip of iceberg in terms of other detectable stellar systems as I expand the survey to cover the entire Northern sky. Therefore, we are on the precipice of conducting the first ever population analysis of the types of stars that emit at radio frequencies, revealing whether they are orbited by exoplanets and what environmental conditions such planets experience.

In the Veni program, I will continue to produce the aforementioned LOFAR survey to explore the origins and physics of radio emission from stellar systems through a two-pronged approach: 1) identifying and following up of the stellar systems found in the LOFAR survey with new high time-frequency capabilities of LOFAR and optical instruments, and 2) perform the first population study to model the environmental properties of exoplanets, and their host stars.

This work will answer outstanding fundamental questions: What space weather conditions do exoplanets experience around radio stars? Could an exoplanetary magnetic field shield a planet in such conditions? Are they potentially habitable?

Details

Project number

VI.Veni.192.167

Main applicant

Dr. J.R. Callingham

Affiliated with

NWO-institutenorganisatie, ASTRON - Netherlands Institute for Radio Astronomy

Duration

01/09/2019 to 31/08/2022