1782 - John Goodricke[?] notices that the brightness variations of Algol are periodic and proposes that it is partially eclipsed by a body moving around it
1964 - Subrahmanyan Chandrasekhar and Richard Feynman develop a general relativistic theory of stellar pulsations and show that supermassive stars are subject to a general relativistic instability
... see Bel
DB is a French automobile maker; see DB (car)
DB is the abbreviation for Deutsche Bahn, the major German railway company
DB is the abbreviation of ...