The corona of GJ 1151 in the context of star-planet interaction

TL;DR

This study reports the first X-ray detection of GJ 1151's corona, revealing a low-temperature, low-luminosity corona that supports models of star-planet interaction as the source of observed radio emissions.

Contribution

First X-ray detection of GJ 1151's corona, providing observational support for star-planet interaction models explaining its radio signals.

Findings

Detected a small flare during X-ray observation.

Measured low coronal temperature of 1.6 MK.

Established an X-ray luminosity consistent with interaction models.

Abstract

The low-mass star GJ 1151 has been reported to display variable low-frequency radio emission, which has been interpreted as a signpost of coronal star-planet interactions with an unseen exoplanet. Here we report the first X-ray detection of GJ 1151's corona based on XMM-Newton data. We find that the star displays a small flare during the X-ray observation. Averaged over the observation, we detect the star with a low coronal temperature of 1.6~MK and an X-ray luminosity of $L_X = 5.5\times 10^{26}$\,erg/s. During the quiescent time periods excluding the flare, the star remains undetected with an upper limit of $L_{X,\,qui} \leq 3.7\times 10^{26}$\,erg/s. This is compatible with the coronal assumptions used in a recently published model for a star-planet interaction origin of the observed radio signals from this star.