RUI: The BRAVA-RR Survey: uncovering an ancient Spheroidal Bulge in the Milky Way

Saint Martin'S University, Lacey WA

Investigators

Abstract

The investigator will observe a special class of old stars, called RR Lyrae stars, located toward the center of the Galaxy. Studying these stars provides a glimpse to how the Milky Way changed with time. The investigator will observe a large sample of these stars in order to reconstruct their motion through space. The reconstructed motions will then allow the investigator to distinguish which RR Lyrae stars are part of the halo, the disk, or the “Spheroidal Bulge” surrounding the center of the Milky Way. These measurements will lead to a better understand the early stages of the Milky Way formation. The investigator will recruit qualified students, targeting first generation and other underrepresented students within the science, technology, engineering and math (STEM) disciplines. These student researchers will collect data from telescopes, analyze the data, and present at conferences. The investigator will continue to lead the popular public science café series, organize star parties and work with the local Boys and Girls club to engage the local community. The investigator will use RR Lyrae stars as test probes to study the formation of the inner Galaxy. Using such ancient and metal-poor stars is important, as most of the stellar populations that have been used to understand the inner Galaxy have been younger and more metal-rich. The oldest stars in the Bulge, like the RR Lyrae stars, were present in the earliest episodes of star formation and assembly of our Galaxy. These observations will be combined with complementary optical surveys to provide the foundation of studies on the structure, dynamics and metallicity of the bulge. This proposal will provide both radial velocities and [Fe/H] metallicities for approximately 5,000 RR Lyrae stars and provide a full orbital analysis of the RR Lyrae stars toward the inner galaxy. 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.