This award will support an observational program to characterize the fundamental properties of massive stars. Dr. Gies and his team will conduct observations of the diameters and flattening of nearby massive stars, obtained with optical interferometry. The first part of this project will determine temperatures, radii, masses, and rotational velocities for a large sample of massive stars. The rotational speeds will be estimated through interferometric measurements of rotational flattening and spectroscopic measurements of the Doppler shifts related to rotation. The second part of the project will examine how close pairs of massive binary stars interact over time exchanging both mass and angular momentum. The observations for this project will be conducted using the Center for High Resolution Astronomy (CHARA) telescope array, located at Mt. Wilson, California.
The project is expected to impact the wider field of stellar astrophysics because the observations will provide key tests of theoretical models for the rotational evolution of massive stars from youth to old age. The project will also involve graduate students at Georgia State University (GSU), and the results from this research will be incorporated into that institution's undergraduate curriculum. The PI also proposes to engage in education and outreach activities in coordination with the Mount Wilson Observatory, and the GSU Hard Labor Creek Observatory in Georgia.
