In his project, Dr. Guinan and collaborators will extend an earlier study on solar-type stars to cooler unevolved stars. The main goals are to measure how stellar rotation slows with time and to explore the relation between ages, rotation rates, and magnetically-driven activity such as chromospheric emission and coronal X-ray flux. The project will study low-mass stars in clusters of known age; if a good age-activity-rotation relation can be found, then the ages of non-cluster stars can be determined.
New satellite experiments are determining a large number of rotation periods and discovering planets around low-mass stars, and it would be important to determine ages for these systems. Determination of the X-ray flux and its evolution will have an impact on whether life would be affected by X-rays on planets in the "habitable zone" of their stars. The project will provide research opportunities for undergraduate students, and will support efforts public in public education and outreach.
