CAREER: A Detailed Look into the Lives of Red Supergiants with Optical Interferometry

Red Supergiants (RSGs) are a late stage in the life cycle of stars of 9 – 25 solar masses. During the RSG stage, these stars experience significant mass-loss, and this lost mass enriches the interstellar medium, playing a significant role in the chemical evolution of the Universe. This project will use high resolution imaging from optical interferometry (OI) to study RSGs. High resolution imaging of stellar surfaces produced via OI enables the study of changes on stellar surfaces at unprecedented detail. Results from this project will help determine the role of convection in driving mass-loss in RSGs. This research will be conducted at New Mexico Tech, a Hispanic serving institution. Two PhD and four undergraduate students will be supported (per year) by this project to collect observations, participate in data reduction, and contribute to model development. Outreach initiatives will involve public talks, volunteering at state-level science competitions, and collaboration with StarDate to produce radio shows that communicate the excitement and results of the research. High resolution imaging of stellar surfaces produced via optical interferometry (OI) enables the study of changes on stellar surfaces at unprecedented detail. This project will use the Center for High Angular Resolution Astronomy (CHARA) Array and Magdalena Ridge Observatory Interferometer (MROI) to collect OI data for image reconstruction of RSGs at different stages of evolution. Stars of angular diameter greater than 4 mas will be used to study both large convection features and smaller granulation-like features. By comparing images reconstructed from data covering continuum wavelengths to those covering molecular bands, it is possible to study the link between surface activity and the formation of molecules further up in the stellar atmosphere. The project will also develop new image reconstruction tools to maximize the scientific output of the data. Techniques and models developed in this program will benefit other users of optical interferometers, and all software will be made publicly accessible. The model refinements will have an impact on other aspects of astrophysics, such as the study of stellar evolution in other galaxies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.