Magnetic field and wind of Kappa Ceti: towards the planetary habitability of the young Sun when life arose on Earth

TL;DR

This study analyzes the magnetic field and stellar wind of Kappa1 Cet, a young Sun proxy, to understand its impact on early Earth's habitability by examining magnetic properties, wind environment, and potential space weather effects.

Contribution

It provides the first detailed magnetic field and wind measurements of Kappa1 Cet, linking stellar activity to early Earth's habitability conditions.

Findings

Kappa1 Cet has a magnetic field and wind strength 50 times greater than the current Sun.

The larger stellar wind could have significantly influenced Earth's early environment.

Enhanced space weather interactions may have affected the development of life on early Earth.

Abstract

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