High Quality Content by WIKIPEDIA articles! Sagittarius A (or Sgr A) is a complex radio source at the center of our galaxy, the Milky Way. It is located in the sky in the Sagittarius constellation. It is hidden from view at optical wavelengths by large clouds of cosmic dust in the spiral arms of the Milky Way. It consists of three components, the supernova remnant Sagittarius A East, the spiral structure Sagittarius A West, and a very bright compact radio source at the center of the spiral, Sagittarius A . These three overlap: Sagittarius A East is the largest, West appears off-center within East, and A is at the center of West.