Tuning in to the radio environment of HD189733b

TL;DR

This paper models the stellar wind of HD189733's host star to predict the planet's radio emission, finding potential detectability with LOFAR, especially during primary transit when wind absorption is minimal.

Contribution

It introduces a model combining stellar magnetic field maps and stellar wind properties to estimate exoplanet radio emission and optimal observation timing.

Findings

Planet's radio emission peaks within LOFAR's detection range.

Stellar wind absorption can significantly attenuate the emission.

Optimal observation time is near the planet's primary transit.

Abstract

The hot Jupiter HD189733b is expected to be a source of strong radio emission, due to its close proximity to its magnetically active host star. Here, we model the stellar wind of its host star, based on reconstructed surface stellar magnetic field maps. We use the local stellar wind properties at the planetary orbit obtained from our models to compute the expected radio emission from the planet. Our findings show that the planet emits with a peak flux density within the detection capabilities of LOFAR. However, due to absorption by the stellar wind itself, this emission may be attenuated significantly. We show that the best time to observe the system is when the planet is near primary transit of the host star, as the attenuation from the stellar wind is lowest in this region.