A Knee-Point in the Rotation-Activity Scaling of Late-type Stars with a Connection to Dynamo Transitions
dc.contributor | Aalto-yliopisto | fi |
dc.contributor | Aalto University | en |
dc.contributor.author | Lehtinen, Jyri J. | en_US |
dc.contributor.author | Käpylä, Maarit J. | en_US |
dc.contributor.author | Olspert, Nigul | en_US |
dc.contributor.author | Spada, Federico | en_US |
dc.contributor.department | Department of Computer Science | en |
dc.contributor.groupauthor | Professorship Korpi-Lagg Maarit | en |
dc.contributor.groupauthor | Centre of Excellence Research on Solar Long-Term Variability and Effects, ReSoLVE | en |
dc.contributor.organization | Max Planck Institute for Solar System Research | en_US |
dc.date.accessioned | 2021-04-20T06:47:08Z | |
dc.date.available | 2021-04-20T06:47:08Z | |
dc.date.issued | 2021-04-01 | en_US |
dc.description | | openaire: EC/H2020/824135/EU//SOLARNET | openaire: EC/H2020/818665/EU//UniSDyn | |
dc.description.abstract | The magnetic activity of late-type stars is correlated with their rotation rates. Up to a certain limit, stars with smaller Rossby numbers, defined as the rotation period divided by the convective turnover time, have higher activity. A more detailed look at this rotation-activity relation reveals that, rather than being a simple power law relation, the activity scaling has a shallower slope for the low-Rossby stars than for the high-Rossby ones. We find that, for the chromospheric CaII H&K activity, this scaling relation is well modelled by a broken two-piece power law. Furthermore, the knee-point of the relation coincides with the axisymmetry to non-axisymmetry transition seen in both the spot activity and surface magnetic field configuration of active stars. We interpret this knee-point as a dynamo transition between dominating axi- and non-axisymmetric dynamo regimes with a different dependence on rotation and discuss this hypothesis in the light of current numerical dynamo models. | en |
dc.description.version | Peer reviewed | en |
dc.format.extent | 8 | |
dc.format.mimetype | application/pdf | en_US |
dc.identifier.citation | Lehtinen, J J, Käpylä, M J, Olspert, N & Spada, F 2021, ' A Knee-Point in the Rotation-Activity Scaling of Late-type Stars with a Connection to Dynamo Transitions ', The Astrophysical Journal, vol. 910, no. 2, 110 . https://doi.org/10.3847/1538-4357/abe621 | en |
dc.identifier.doi | 10.3847/1538-4357/abe621 | en_US |
dc.identifier.issn | 0004-637X | |
dc.identifier.other | PURE UUID: 49fd8e07-370c-4c83-b922-1c8625310417 | en_US |
dc.identifier.other | PURE ITEMURL: https://research.aalto.fi/en/publications/49fd8e07-370c-4c83-b922-1c8625310417 | en_US |
dc.identifier.other | PURE LINK: http://www.scopus.com/inward/record.url?scp=85103677481&partnerID=8YFLogxK | en_US |
dc.identifier.other | PURE LINK: https://arxiv.org/abs/2007.00040 | en_US |
dc.identifier.other | PURE LINK: http://adsabs.harvard.edu/abs/2020arXiv200700040L | en_US |
dc.identifier.other | PURE FILEURL: https://research.aalto.fi/files/53596410/2007.00040 | en_US |
dc.identifier.uri | https://aaltodoc.aalto.fi/handle/123456789/106867 | |
dc.identifier.urn | URN:NBN:fi:aalto-202104206161 | |
dc.language.iso | en | en |
dc.publisher | IOP Publishing Ltd. | |
dc.relation | info:eu-repo/grantAgreement/EC/H2020/818665/EU//UniSDyn | en_US |
dc.relation.ispartofseries | Astrophysical Journal | en |
dc.relation.ispartofseries | Volume 910, issue 2 | en |
dc.rights | openAccess | en |
dc.subject.keyword | Astrophysics - Solar and Stellar Astrophysics | en_US |
dc.title | A Knee-Point in the Rotation-Activity Scaling of Late-type Stars with a Connection to Dynamo Transitions | en |
dc.type | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä | fi |