Stellar magnetic field manifestations such as stellar winds and EUV radiation are the key drivers of planetary atmospheric loss and escape. To understand how the central star influences habitability, it is very important to perform detailed investigation of the star’s magnetic field. We investigate the surface magnetic field geometry and chromospheric activity of 51 sun-like stars. The magnetic geometry is reconstructed using Zeeman Doppler imaging. Chromospheric activity is measured using the Ca II H& K lines. We confirm that the Sun’s large-scale geometry is dominantly poloidal, which is also true for slowly rotating stars. Contrary to the Sun, rapidly rotating stars can have a strong toroidal field and a weak poloidal field. This separation in field geometry appears at Ro=1. Our results show that detailed investigation of stellar magnetic field is important to understand its influence on planetary habitability.
