The X-Ray View of Stellar Cycles

With the advent of largescale optical photometric monitoring and exoplanetsearch programs, the number of stars with known stellar cycles has rapidlygrown. In parallel, advances in theoretical modeling are leading to a revolutionin our understanding of stellar structure and magnetic field generation inlatetype stars. Still, many questions remain, and new puzzles have arisen, suchas the existence of cycles in fully convective stars. Xray emission is a keydiagnostic of stellar magnetic activity, and Xray cycle amplitudes are muchlarger than in the optical, but of the hundreds of stars with confirmed cycles,only seven have been monitored in X rays. We request XMMNewton observations ofthree stars that will significantly broaden the Xray perspective on stellar cycles. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]