Observing and modelling the young solar analogue EK Draconis: starspot distribution, elemental abundances, and evolutionary status

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dc.authoridHussain, Gaitee/0000-0003-3547-3783
dc.authoridIsik, Emre/0000-0001-6163-0653
dc.authoridSenavci, Hakan Volkan/0000-0002-8961-277X
dc.authoridMontes, David/0000-0002-7779-238X
dc.authoridBAHAR, ENGIN/0000-0001-9119-2316
dc.authoridKilicoglu, Tolgahan/0000-0001-6947-822X
dc.contributor.authorSenavci, H., V
dc.contributor.authorKilicoglu, T.
dc.contributor.authorIsik, E.
dc.contributor.authorHussain, G. A. J.
dc.contributor.authorMontes, D.
dc.contributor.authorBahar, E.
dc.contributor.authorSolanki, S. K.
dc.date.accessioned2025-02-20T08:42:16Z
dc.date.available2025-02-20T08:42:16Z
dc.date.issued2021
dc.departmentTürk-Alman Üniversitesien_US
dc.description.abstractObservations and modelling of stars with near-solar masses in their early phases of evolution are critical for a better understanding of how dynamos of solar-type stars evolve. We examine the chemical composition and the spot distribution of the pre-mainsequence solar analogue EK Dra. Using spectra from the HERMES Spectrograph (La Palma), we obtain the abundances of 23 elements with respect to the solar ones, which lead to a [Fe/H] = 0.03, with significant overabundance of Li and Ba. The s-process elements Sr, Y, and Ce are marginally overabundant, while Co, Ni, Cu, Zn are marginally deficient compared to solar abundances. The overabundance of Ba is most likely due to the assumption of depth-independent microturbulent velocity. Li abundance is consistent with the age and the other abundances may indicate distinct initial conditions of the pre-stellar nebula. We estimate a mass of 1.04 M-circle dot and an age of 27(-8)(+11) Myr using various spectroscopic and photometric indicators. We study the surface distribution of dark spots, using 17 spectra collected during 15 nights using the CAFE Spectrograph (Calar Alto). We also conduct flux emergence and transport (FEAT) simulations for EK Dra's parameters and produce 15-d-averaged synoptic maps of the likely starspot distributions. Using Doppler imaging, we reconstruct the surface brightness distributions for the observed spectra and FEAT simulations, which show overall agreement for polar and mid-latitude spots, while in the simulations there is a lack of low-latitude spots compared to the observed image. We find indications that cross-equatorial extensions of mid-latitude spots can be artefacts of the less visible southern-hemisphere activity.
dc.description.sponsorshipScientific and Technological Research Council of Turkey (TUBITAK) [1001 -115F033]; Spanish Ministry of Economy and Competitiveness (MINECO) [AYA2016-79425-C31-P]; BK21 plus program through the National Research Foundation (NRF) - Ministry of Education of Korea
dc.description.sponsorshipWe would like to thank S.P. Jarvinen for providing the data used in Fig. 11, Oleg Kochukov (Uppsala University) for his useful comments concerning the effect of the magnetic field on the derived abundances, and the referee, Pascal Petit, whose critical comments led to substantial improvement of the manuscript. HVS acknowledges the support by the Scientific and Technological Research Council of Turkey (TUBITAK) through the project 1001 -115F033. DM acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) from project AYA2016-79425-C31-P. This work has made use of data from the European Space Agency (ESA) mission. This work has been partially supported by the BK21 plus program through the National Research Foundation (NRF) funded by the Ministry of Education of Korea.
dc.identifier.doi10.1093/mnras/stab199
dc.identifier.endpage3356en_US
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.issue3en_US
dc.identifier.scopus2-s2.0-85121556701
dc.identifier.scopusqualityQ1
dc.identifier.startpage3343en_US
dc.identifier.urihttps://doi.org/10.1093/mnras/stab199
dc.identifier.urihttps://hdl.handle.net/20.500.12846/1613
dc.identifier.volume502en_US
dc.identifier.wosWOS:000648998800013
dc.identifier.wosqualityQ1
dc.indekslendigikaynakWeb of Science
dc.indekslendigikaynakScopus
dc.language.isoen
dc.publisherOxford Univ Press
dc.relation.ispartofMonthly Notices of the Royal Astronomical Society
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanı
dc.rightsinfo:eu-repo/semantics/openAccess
dc.snmzKA_WOS_20250220
dc.subjectstars: abundancesen_US
dc.subjectstars: activityen_US
dc.subjectstars: imagingen_US
dc.subjectstars: individual: EK Draen_US
dc.subjectstarspotsen_US
dc.titleObserving and modelling the young solar analogue EK Draconis: starspot distribution, elemental abundances, and evolutionary status
dc.typeArticle

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