Dr. McSwain is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Yale University in New Haven, Connecticut. Recent stellar models show that the evolution of massive stars is dependent not only on their initial mass and heavy metal content, but also on their rotation. Models also show that rotational mixing causes significant abundance changes at the stellar surface, especially among He and the CNO elements, well before the convective zone deepens during the red supergiant phase. However, the rotating stellar models are not yet fully constrained, and observational evidence of such abundance changes is limited. In this study, Dr. McSwain will perform a spectroscopic and photometric study of the OB populations of 20 open clusters. For each cluster member, its age, rotational velocity, and He/CNO abundances will be measured. This investigation will form the backbone of observations of rotational mixing in massive stars, and the results will provide important constraints that will improve evolutionary models of massive stars.
To promote astronomy education in the inner-city public schools of New Haven, Dr. McSwain will develop several 6-week long astronomy laboratory units for grades K-4, 5-8, and 9-12 in coordination with the educational program at the Peabody Museum of Natural History. Each unit will culminate with an observing session at the Yale Student Observatory where students will be able to apply their classroom lessons to first-hand observations of the night sky.
