I'm always fascinated with the Galactic Center - from unexplained tones that emanate from within to things that sparkle and others that go bump in the night. The Galactic Center is, after all, the eye (blackhole) through which all returns.

Tuesday, on the Astronomy Picture of the Day we find mention of something called, Baade's Window named for astrophysicist Walter Baade. (Why do I feel I knew him in Germany and we shared ideas?)

Baade's Window is a region with relatively low amounts of interstellar "dust" along our line of sight and is a "window" because in this direction we are able to see all the way to the Milky Way Galactic Center (actually, somewhat "south" of the center, in the central bulge) and beyond. It is named after the German astronomer Walter Baade. Baade's Window is used to inspect distant stars and to determine the internal geometry of the Milky Way. It lies towards the constellation of Sagittarius. The window is irregular in outline, but is about 1 degree wide and is centered around the globular cluster NGC 6522. This corresponds to one of the brightest patches of the Milky Way in Sagittarius. Baade's Window is one of six small zones through which some of the central bulge stars are visible.

Wilhelm Heinrich Baade (March 24, 1893 - June 25, 1960) was a German astronomer and astrophysicists who emigrated to the USA in 1931. During World War II, he took advantage of wartime blackout conditions which reduced light pollution at Mount Wilson Observatory, to observe stars in the center of the Andromeda galaxy for the first time. This led him to define distinct "populations" for stars (Population I and Population II). The same observations led him to discover that there are two types of Cepheid variable stars. This discovery led him to recalculate the size of the known universe, doubling the previous calculation made by Hubble in 1929. He announced this finding to considerable astonishment at the 1952 meeting of the International Astronomical Union in Rome. Together with Fritz Zwicky, he identified supernovae as a new category of astronomical objects. Zwicky and he also proposed the existence of neutron stars, and proposed that supernovae could create neutron stars. He identified the optical counterparts of various radio sources. He discovered 10 asteroids, including notably 944 Hidalgo (long orbital period) and the Apollo-class asteroid 1566 Icarus (whose perihelion is closer than that of Mercury) and the Amor asteroid 1036 Ganymed.