The turbulent evolution of activity cycles | Jorge Sanz-Forcada ( CAB – Madrid, Spain)

Activity cycles are of major interest to understand the solar physics and the influence of the Sun in the Earth’s climate. The effects of solar activity in the Earth are mainly produced by the high energy photons and particles. The solar coronal cycle varies as much as a factor of 50, as measured in terms of Lx. But there is little known on the amplitude of this cycle in the past. So far there were only three stars others than the Sun with a known coronal cycle, all of them in rather old K dwarfs with low activity levels. In a recent paper we have found the coronal cycle of Iota Horologii, the star with the shortest chromospheric cycle known to date. This star represents the first coronal cycle in an active star, in a G dwarf, and in a young star. Iota Hor is a solar-like star with an age of ~600 Myr, the age at which the life appeared on Earth. This cycle may represent the first coronal cycles in the evolution of a solar-like star.