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dc.contributor.authorGibb, Gordon Peter Samuel
dc.contributor.authorJardine, Moira Mary
dc.contributor.authorMackay, Duncan Hendry
dc.identifier.citationGibb , G P S , Jardine , M M & Mackay , D H 2014 , ' Stellar differential rotation and coronal time-scales ' , Monthly Notices of the Royal Astronomical Society , vol. 433 , no. 4 , pp. 3251-3259 .
dc.identifier.otherORCID: /0000-0001-6065-8531/work/58055423
dc.identifier.otherORCID: /0000-0002-1466-5236/work/57821817
dc.descriptionGPSG would like to thank the STFC for financial support. DHM would like to thank the STFC and the Leverhulme Trust for financial support.en
dc.description.abstractWe investigate the time-scales of evolution of stellar coronae in response to surface differential rotation and diffusion. To quantify this, we study both the formation time and lifetime of a magnetic flux rope in a decaying bipolar active region. We apply a magnetic flux transport model to prescribe the evolution of the stellar photospheric field, and use this to drive the evolution of the coronal magnetic field via a magnetofrictional technique. Increasing the differential rotation (i.e. decreasing the equator-pole lap time) decreases the flux rope formation time. We find that the formation time is dependent upon the lap time and the surface diffusion time-scale through the relation tau_Form ∝ &surd;{tau_Laptau_Diff}. In contrast, the lifetimes of flux ropes are proportional to the lap time (tauLife∝tauLap). With this, flux ropes on stars with a differential rotation of more than eight times the solar value have a lifetime of less than 2 d. As a consequence, we propose that features such as solar-like quiescent prominences may not be easily observable on such stars, as the lifetimes of the flux ropes which host the cool plasma are very short. We conclude that such high differential rotation stars may have very dynamical coronae.
dc.relation.ispartofMonthly Notices of the Royal Astronomical Societyen
dc.subjectStars: activityen
dc.subjectStars: coronaeen
dc.subjectStars: magnetic fielden
dc.subjectStars: rotationen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.titleStellar differential rotation and coronal time-scalesen
dc.typeJournal articleen
dc.contributor.sponsorScience & Technology Facilities Councilen
dc.contributor.sponsorScience & Technology Facilities Councilen
dc.contributor.sponsorThe Leverhulme Trusten
dc.contributor.institutionUniversity of St Andrews. Applied Mathematicsen
dc.contributor.institutionUniversity of St Andrews. School of Physics and Astronomyen
dc.description.statusPeer revieweden

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