This project will study B-type stars, which are much more massive than the Sun, live for relatively short time, and have disk-like features around them. These stars expel a great deal of mass to interstellar space. Thus, they are important to understanding how our Galaxy has changed over time. The researchers will use the Navy Precision Optical Interferometer (NPOI) in Arizona, which combines data from six telescopes to create highly detailed images. They will produce spatially resolved stellar surfaces and search for gaps and ring-like structures in the disks. The team will also use the nearby John Hall telescope to measure the chemical composition and physical processing occurring in the disks. Undergraduate and graduate students will participate in the research. The PI will work with Central Michigan University?s Center for Excellence in STEM Education to conduct a teacher workshop.<br/><br/>The NPOI facility is sensitive to the light of the hydrogen-alpha line, which is among the most prominent emission lines produced by the high temperatures associated with these disks. These data will make it possible to place strong constraints on temperature, density, total mass, and angular momentum of 35 of these stars. The time-resolved data will also make it possible to investigate the effects of any binary companions on the circumstellar disks. The PI<br/>Will teach students data reduction techniques in an Observational Astronomy course for undergraduate and graduate students. <br/> graduate students.