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dc.contributor.authorKavanagh, Robert D
dc.contributor.authorVidotto, Aline A
dc.contributor.authorVedantham, Harish K
dc.contributor.authorJardine, Moira M
dc.contributor.authorCallingham, Joe R
dc.contributor.authorMorin, Julien
dc.identifier.citationKavanagh , R D , Vidotto , A A , Vedantham , H K , Jardine , M M , Callingham , J R & Morin , J 2022 , ' Radio masers on WX UMa : hints of a Neptune-sized planet, or magnetospheric reconnection? ' , Monthly Notices of the Royal Astronomical Society , vol. 514 , no. 1 , stac1264 , pp. 675–688 .
dc.identifier.otherPURE: 279545381
dc.identifier.otherPURE UUID: e55f30b1-a77b-4201-a23a-bfa80d89ad58
dc.identifier.otherBibtex: 10.1093/mnras/stac1264
dc.identifier.otherScopus: 85133597459
dc.identifier.otherORCID: /0000-0002-1466-5236/work/116598113
dc.identifier.otherWOS: 000808232400005
dc.descriptionFunding: RDK acknowledges funding received from the Irish Research Council (IRC) through the Government of Ireland Postgraduate Scholarship Programme. RDK and AAV acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 817540, ASTROFLOW). We acknowledge the provisions of the Space Weather Modelling Framework (SWMF) code from the Center for Space Environment Modeling (CSEM) at the University of Michigan, and the computational resources of the Irish Centre for High End Computing (ICHEC), both of which were utilised in this work.en
dc.description.abstractThe nearby M dwarf WX UMa has recently been detected at radio wavelengths with LOFAR. The combination of its observed brightness temperature and circular polarisation fraction suggests that the emission is generated via the electron-cyclotron maser instability. Two distinct mechanisms have been proposed to power such emission from low-mass stars: either a sub-Alfvénic interaction between the stellar magnetic field and an orbiting planet, or reconnection at the edge of the stellar magnetosphere. In this paper, we investigate the feasibility of both mechanisms, utilising the information about the star’s surrounding plasma environment obtained from modelling its stellar wind. Using this information, we show that a Neptune-sized exoplanet with a magnetic field strength of 10 – 100 G orbiting at ∼0.034 au can accurately reproduce the observed radio emission from the star, with corresponding orbital periods of 7.4 days. Due to the stellar inclination, a planet in an equatorial orbit is unlikely to transit the star. While such a planet could induce radial velocity semi-amplitudes from 7 to 396 m s−1, it is unlikely that this signal could be detected with current techniques due to the activity of the host star. The application of our planet-induced radio emission model here illustrates its exciting potential as a new tool for identifying planet-hosting candidates from long-term radio monitoring. We also develop a model to investigate the reconnection-powered emission scenario. While this approach produces less favourable results than the planet-induced scenario, it nevertheless serves as a potential alternative emission mechanism which is worth exploring further.
dc.relation.ispartofMonthly Notices of the Royal Astronomical Societyen
dc.rightsCopyright © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at
dc.subjectStars: individual: WX UMaen
dc.subjectStars: windsen
dc.subjectStars: mass-lossen
dc.subjectStars: magnetic fielden
dc.subjectRadio continuum: planetary systemsen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.titleRadio masers on WX UMa : hints of a Neptune-sized planet, or magnetospheric reconnection?en
dc.typeJournal articleen
dc.contributor.institutionUniversity of St Andrews. School of Physics and Astronomyen
dc.description.statusPeer revieweden

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