The Visible spEctroGraph and polArimeter (VEGA) was installed in September 2007 at the CHARA array. VEGA measures spectrally dispersed interference fringes, providing a spatial resolution of 0.3 mas and spectral resolutions from R = 6,000 to 30,000 over a wavelength of 480-850nm. VEGA can be used to measure the fundamental properties of stars, study their stellar activity, and analyze the spatial and kinematic properties of their circumstellar environments.
VEGA: Visible spEctroGraph and polArimeter for the CHARA array: principle and performance - Mourard et al. 2009, A&A, 508, 1073 (pdf)