Coronal activity cycles in solar analog stars

The present monitoring program to identify and study for the first time thecyclic behavior of the coronal emission of stars similar to our Sun has beenongoing since XMM.s AO1. Five stars in three stellar systems have beenmonitored at regular cadence for over a decade, providing the first clearevidence of longterm cycles in the coronal activity of normal stars, withamplitudes of up to an order of magnitude in Xray luminosity. The presentproposal requests continuation of the monitoring program into AO14. Our bestobserved targets, HD81809 and 61Cyg A, have both been observed through more thana full cycle, while a cycle is starting to become evident in the observations ofa Cen B. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]