(1893-1960) German-born US astronomer who made observations that doubled the distance, scale, and age of the universe. He discovered that stars are in two distinct populations according to their age, known as Population I (the younger) and Population II (the older). Later, he found that Cepheid variable stars of Population I are brighter than had been supposed and that distances calculated from them were wrong.
Baade, born in Shröttinghausen, studied at Münster and Göttingen. He emigrated to the US 1931, working at Mount Wilson Observatory, Pasadena, California, until 1948 and nearby Mount Palomar Observatory until 1958, when he returned to Germany.
During World War II, in 1943, Baade made use of the blackout darkness to study the Andromeda galaxy and was able to observe, for the first time, some of the stars in the inner regions of the galaxy. He found that the most luminous stars toward the center are not blue-white but reddish, and proposed that these have differing structures and origins. Population I stars, bluish, are young and formed from the dusty material of the spiral arms—hydrogen, helium, and heavier elements; Population II stars, reddish, are old, were created near the nucleus and contain fewer heavy elements.

Množina: Baader-Meinhof gangs

Popular name for the West German left-wing guerrilla group the Rote Armee Fraktion/Red Army Faction, active from 1968 against what it perceived as US imperialism. The three main founding members were Andreas Baader (1943–1977), Gudrun Ensslin, and Ulrike Meinhof (1934–1976).
The group carried out a succession of terrorist attacks in West Germany during the 1970s and claimed responsibility 1990 for the murder of Detlev Rohwedder, the government agent responsible for selling off state-owned companies of the former East German regime.
A former student activist, Baader was sentenced to life imprisonment in April 1977; he took his own life in Oct, following the failure of the Faction's hostage swap attempt at Mogadishu airport.