J/A+A/667/A50ivo://CDS.VizieR/J/A+A/667/A50doi:10.26093/cds/vizier.36670050CDSNoraz Q.Breton S.N.Brun A.S.Garcia R.A.Strugarek A.Santos A.R.G.,Mathur S.Amard L.2024-11-06T20:01:17Z2022-11-04T09:46:27ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frg-starsAnti-solar differential rotation profiles have been found for decades in numerical simulations of convective envelopes of solar-type stars. These profiles are characterized by a slow equator and fast poles (i.e., reversed with respect to the Sun) and have been found in simulations for high Rossby numbers. Rotation profiles like this have been reported in evolved stars, but have never been unambiguously observed for cool solar-type stars on the main sequence. As solar-type stars age and spin down, their Rossby numbers increase, which could therefore induce a transition toward an anti-solar differential rotation regime before the end of the main sequence. Such a rotational transition will impact the large-scale dynamo process and the magnetic activity. In this context, detecting this regime in old main-sequence solar-type stars would improve our understanding of their magnetorotational evolution. The goal of this study is to identify the most promising cool main-sequence stellar candidates for anti-solar differential rotation in the Kepler sample. First, we introduce a new theoretical formula to estimate fluid Rossby numbers, Rof, of main-sequence solar-type stars. We derived it from observational quantities such as Teff and Prot, and took the influence of the internal structure into account. Then, we applied it on a subset of the most recent catalog of Kepler rotation periods, after removing subgiants and selecting targets with solar metallicity. Next, we considered the highest computed Rof and inspected each target individually to select the most reliable anti-solar candidate. Finally, we extended our study to stars with metallicities different from that of the Sun. To this end, we developed a formulation for Rof dependent on the metallicity index [Fe/H] by using 1D stellar grids, and we also considered this compositional aspect for the selection of the targets. We obtain a list of the most promising stars that are likely to show anti-solar differential rotation. We identify two samples: one at solar metallicity, including 14 targets, and another for other metallicities, including 8 targets. We find that the targets with the highest Rof are likely to be early-G or late-F stars at about log10g=4.37dex. We conclude that cool main-sequence stellar candidates for anti-solar differential rotation exist in the Kepler sample. The most promising candidate is KIC 10907436, and two other particularly interesting candidates are the solar analog KIC 7189915 and the seismic target KIC 12117868. Future characterization of these 22 stars is expected to help us understand how dynamics can impact magnetic and rotational evolution of old solar-type stars at high Rossby number.2022A&A...667A..50Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/667/A50CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/667/A50https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/667/A50http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/667/A50https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/667/A50https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/667/A50http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/667/A50GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/667/A50/tablec1 (Results of individual visual inspections)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/667/A50/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/667/A50/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/667/A50/tablec1?GETtext/xml+votable180.050000true286.123537.34180110.0055555555555555565/3647 3734 6/14573 14578 14582-14583 14585-14587 14733 14735 14746 14751 14753 14757-14758 14764-14765 14770-14771 14773-14774 14776-14777 14779 14792 14816 14825 14828 14914 14920-14921 14923-14924 14929 14931 14933 14940 14942 14948 14950-14951 14953-14954 14957-14958 14960-14961 14972 15061-15062 15107 15113 15115-15116 15118-15122 15124-15126 15129 15132 15134-15135 15137 15143 15145 15158 15171-15172 15174https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/667/A50?format=asciidefaultJ/A+A/667/A50/tablec1Results of individual visual inspectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKICKepler Input Catalog identifiermeta.id;meta.mainintHaloFlag[0/1] Target in bright Halo (1)meta.codeintNeighFlag[0/3] Neighbors in FoV (2)meta.codeintShapeFlag[0/1] Suspicious shape (3)meta.codeintloggFlag[0/1] High logg uncertainties (4)meta.codeintProtFlag[0/3] Uncertain rotation period (5)meta.codeintCandFlag[0/1] Antisolar candidate (6)meta.codeint_RAPostions from KIC (Cat. V/133) (right ascension part)degpos.eq.ra;meta.main_DEPostions from KIC (Cat. V/133) (declination part)degpos.eq.dec;meta.main