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luminosity

(Encyclopedia)luminosity, in astronomy, the rate at which energy of all types is radiated by an object in all directions. A star's luminosity depends on its size and its temperature, varying as the square of the ra...

Mitchell, Maria

(Encyclopedia)Mitchell, Maria, 1818–89, American astronomer and educator, b. Nantucket, Mass. Mitchell taught school in Nantucket, and later became a librarian. On Oct. 1, 1847, Mitchell discovered a comet (1847 ...

spectroscope

(Encyclopedia)spectroscope, optical instrument for producing spectral lines and measuring their wavelengths and intensities, used in spectral analysis (see spectrum). When a material is heated to incandescence it e...

Cerro Tololo Inter-American Observatory

(Encyclopedia)Cerro Tololo Inter-American Observatory sāˈrō tōlōˈlō [key], astronomical observatory located on Cerro Tololo peak, Chile, with offices in La Serena, about 40 mi (64 km) to the west. Funded by ...

Carruthers, George Richard

(Encyclopedia) Carruthers, George Richard, 1939-2020, African-American astrophysicist, b. Cincinnati, OH, Univ. of Illinois at Urbana-Champaign (BS, 1961; MS, nuclear...

Orbiting Astronomical Observatory

(Encyclopedia)Orbiting Astronomical Observatory (OAO), series of four orbiting observatories (see observatory, orbiting) launched between 1966 and 1972 by the National Aeronautics and Space Administration (NASA) to...

lock and key

(Encyclopedia)lock and key, fastening fitted to an entryway, such as a gate or door, or a container, such as a cabinet, drawer or safe, to keep it closed and/or prevent unauthorized access or use. Locks typically c...

Amboise

(Encyclopedia)Amboise äNbwäzˈ [key], town, Indre-et-Loire dept., N central France, in Touraine, on the Loire. It is a wine and wool market, and its manufactures include sporting good...

Hildesheim

(Encyclopedia)Hildesheim hĭlˈdəs-hīm [key], city, Lower Saxony, N central Germany. The city is an industrial ...

Forssmann, Werner

(Encyclopedia)Forssmann, Werner vĕrˈnər fôrsˈmän [key], 1904–79, German physician and physiologist, M.D. Univ. of Berlin (1929). In the late 1920s, he developed the technique of cardiac catheterization, whe...