Magnetic Fields Throughout Stellar Evolution Proceedings IAU Symposium No. 302, 2013 P. Petit, M.M. Jardine & H.C. Spruit, eds. c  2013 International Astronomical Union DOI: 00.0000/X000000000000000X High-resolution spectropolarimetric of κ Cet: A proxy for the young Sun J.D. do Nascimento Jr 1 , P. Petit 2 , S. Marsden 3 , G. F. Porto de Mello 4 , I. Ribas 5 , S. Jeffers 6 , M. Castro 1 , E. Guinan 7 and the Bcool Collaboration 1 DFTE, Univ. Federal do R. Grande do Norte, 59072-970 Natal, RN, Brazil email: dias@dfte.ufrn.br 2 IRAP, CNRS, 14 Av. Edouard Belin, F-31400 Toulouse, France 3 CESRC, Univ. of Southern Queensland, Toowoomba, 4350, Australia 4 OV, UFRJ, L. do Pedro Antˆ onio, 43 20080-090 Rio de Janeiro, RJ, Brazil 5 IES de Catalunya, UAB, F. de Ci` encies, Torre, 08193 Bellaterra, Spain 6 IAG, Georg-August-Univ. G¨ ottingen, Friedrich-Hund-Platz 1, 37077 G¨ ottingen, Germany 7 Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085; US Abstract. Keywords. κ 1 Cet , HD 20630, HIP 15457, solar analogs, magnetic field Among the solar proxies studied in the Sun in Time κ 1 Cet (HD 20630) stands out as potentially having a mass very close to solar and a young age. On this study, we monitored the magnetic field and the chromospheric activity from the Ca II H & K lines of κ 1 Cet. We used the Least-Square-Deconvolution (LSD, Donati et al. 1997) by simultaneously extracting the information contained in all 8,000 photospheric lines of the echelogram (K1 type star). To reconstruct a reliable magnetic map and characterize the surface differential rotation of κ 1 Cet we used 14 exposures spread over 2 months, in order to cover at least two rotational cycles (Prot ∼ 9.2 days). The LSD technique was applied to detect the Zeeman signature of the magnetic field in each of our 14 observations and to measure its longitudinal component. In order to reconstruct the magnetic field geometry of κ 1 Cet , we applied the Zeeman Doppler Imaging (ZDI) inversion method. ZDI revealed a structure in the radial magnetic field consisting of a polar magnetic spot. On this study, we present the fisrt look results of a high-resolution spectropolarimetric campaign to characterize the activity and the magnetic fields of this young solar proxy. 1. Introduction The observational programme Sun in Time is focused on a small sample of carefully- selected and well-studied stellar proxies that well represent some key stages in the evo- lution of the Sun. Among the solar proxies studied in the Sun in Time, κ 1 Cet stands out as potentially having a mass and metallicity very close to solar with an estimated age of ∼ 0.7 Gyr (Ribas et al. 2005). This could be a very good analog of the Sun at the critical time when life is thought to have originated on Earth 3.8 Gyr ago. The star was discovered to have a rapid rotation, roughly once every nine days. κ 1 Cet is also consid- ered a good candidate to contain terrestrial planets. In spite of our in-depth knowledge of κ 1 Cet , including its radiative properties, abundances, atmospheric parameters, and evolutionary state, we know little or nothing about the magnetic field properties of this important solar proxy. On this study we present the first look results from a regularly ob- servational campaign using the NARVAL spectropolarimeter at the T´ elescope Bernard 1 arXiv:1310.7620v1 [astro-ph.SR] 28 Oct 2013