%0 Journal Article %T Magnetic field and wind of Kappa Ceti: towards the planetary habitability of the young Sun when life arose on Earth %+ Observatoire Astronomique de l'Université de Genève (ObsGE) %+ Institut de recherche en astrophysique et planétologie (IRAP) %+ Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) %+ Univ. Federal do Rio G. do Norte %+ Computational Engineering and Science Research Centre %+ Laboratoire Univers et Particules de Montpellier (LUPM) %+ Obs. do Valongo %+ Institut für Astrophysik [Göttingen] %+ Institut de Ciències de l'Espai %A Nascimento, J. -D. Do %A Vidotto, A. A. %A Petit, Pascal %A Folsom, Colin P. %A Castro, Matthieu %A Marsden, S. C. %A Morin, Julien %A Porto de Mello, G. F. %A Meibom, Søren %A Jeffers, S. V. %A Guinan, E. %A Ribas, I. %Z 6 pages, 5 figures, Published at the Astrophysical Journal Letters (ApJL): Manuscript #LET33582 %< avec comité de lecture %Z LUPM:16-008 %@ 2041-8205 %J The Astrophysical journal letters %I Bristol : IOP Publishing %P L15 %8 2016-03-16 %D 2016 %Z 1603.03937 %R 10.3847/2041-8205/820/1/L15 %K stars: individual: HD 20630 %K HIP 15457 %K stars: magnetic field %K stars: winds %K outflows %Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] %Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]Journal articles %X We report magnetic field measurements for Kappa1~Cet, a proxy of the young Sun when life arose on Earth. We carry out an analysis of the magnetic properties determined from spectropolarimetric observations and reconstruct its large-scale surface magnetic field to derive the magnetic environment, stellar winds and particle flux permeating the interplanetary medium around Kappa1~Cet. Our results show a closer magnetosphere and mass-loss rate of Mdot = 9.7 x 10^{-13} Msol/yr, i.e., a factor 50 times larger than the current solar wind mass-loss rate, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the planet's habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions %G English %Z Bcool %L hal-01769975 %U https://hal.science/hal-01769975 %~ IN2P3 %~ INSU %~ METEO %~ UNIV-SAVOIE %~ UNIV-TLSE3 %~ UGA %~ CNRS %~ INPG %~ IRSTEA %~ CNES %~ OSUG %~ OMP %~ OMP-IRAP %~ LUPM %~ IPAG %~ AGREENIUM %~ UNIV-MONTPELLIER %~ LUPM_AS %~ INRAE %~ UGA-COMUE %~ USMB-COMUE %~ UNIV-UT3 %~ UT3-INP %~ UT3-TOULOUSEINP %~ UM-2015-2021