Baade's Window with the two globular clusters NGC 6522 (right) and NGC 6528, photographed with the 3.9-meter Anglo-Australian Telescope. Credit: David Malin
A small clearing in the dust clouds of Sagittarius, near the globular cluster NGC 6522, through which astronomers can view stars in the galactic bulge. The window lies 3.9° south of the galactic center, corresponding to a line of sight that passes within 1,800 light-years of the Milky Way’s heart. It is named after Walter Baade who used it to observe RR Lyrae variables in the bulge region.