Sydney Barnes
Dr. Barnes works in the field of stellar astronomy, with an emphasis on sun-like stars. He enjoys working at the interface between theory and observations, particularly on topics related to the global and dynamical properties of stars, and their changes with stellar age. He has a special interest in understanding how stars rotate, and why they do so at the measured rates. Major results of his work include the identification of patterns in the distribution of stellar rotation periods, an explanation of these in terms of stellar magnetism, and gyrochronology, a new way of deriving the ages of individual stars.
Gyrochronology
December 8, 2011
When: December 8, 2011 4:00PM
Sydney Barnes
Lowell Observatory
Gyrochronology is a method of deriving the precise age of a cool star from its measured rotation period, itself derived from photometric time-series observations from the ground or from space. Although derived originally using open-cluster observations, it can potentially be applied on a massive scale to field stars, permitting the construction of the "histories" of astronomical phenomena, and even a "chronology of the Galaxy." I will relate the empirical origins of gyrochronology, and connect these to relevant theoretical issues in cool star rotation and activity. A hybrid of theoretical and observational approaches seems to promise the best ages, including pointers for removing errors in prior age determination methods, and insights into the underlying physics. Finally, I will outline how small surveys are changing, and large surveys could potentially revolutionize, our understanding of the ages of astronomical objects, and of related evolutionary processes in the Galaxy.
