Exoplanet-induced radio emission from M-dwarfs

TL;DR

This paper models the magnetic interactions between exoplanets orbiting M-dwarfs and their host stars, predicting detectable radio emissions caused by electron-cyclotron maser instability, with potential for future astronomical observations.

Contribution

It introduces a new model for exoplanet-induced radio emissions from M-dwarfs and applies it to specific systems, identifying candidates for radio detection.

Findings

Predicted radio flux densities up to 10 μJy steady and 1 mJy in bursts.

Identified 11 exoplanets capable of producing detectable radio signals.

Suggests current and future radio telescopes can observe these emissions.

Abstract

We consider the magnetic interaction of exoplanets orbiting M-dwarfs, calculating the expected Poynting flux carried upstream along Alfv\'{e}n wings to the central star. A region of emission analogous to the Io footprint observed in Jupiter's aurora is produced, and we calculate the radio flux density generated near the surface of the star via the electron-cyclotron maser instability. We apply the model to produce individual case studies for the TRAPPIST-1, Proxima Centauri, and the dwarf NGTS-1 systems. We predict steady-state flux densities of up to ~ 10 $\mu$Jy and sporadic bursts of emission of up to ~ 1 mJy from each case study, suggesting these systems may be detectable with the Very Large Array (VLA) and the Giant Metrewave Radio Telescope (GMRT), and in future with the Square Kilometre Array (SKA). Finally, we present a survey of 85 exoplanets orbiting M-dwarfs, identifying 11 such objects capable of generating radio emission above 10 $\mu$Jy.