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X-ray astronomy

(Encyclopedia)X-ray astronomy, study of celestial objects by means of the X rays they emit, in the wavelength range from 0.01 to 10 nanometers. X-ray astronomy dates to 1949 with the discovery that the sun emits X ...

In

(Encyclopedia)In, symbol for the element indium. ...

Albumazar

(Encyclopedia)Albumazar älˌbo͞omäˈzər [key], 805?–885, Arab astronomer, more fully Abu-Mashar Jafar ibn Muhammad. In his De magnis conjunctionibus he claimed that the world had been created when the seven p...

National Radio Astronomy Observatory

(Encyclopedia)National Radio Astronomy Observatory (NRAO), federal observatory for radio astronomy, founded in 1956 and operated under contract with the National Science Foundation by Associated Universities, Inc.,...

Nuffield Radio Astronomy Laboratories

(Encyclopedia)Nuffield Radio Astronomy Laboratories: see Jodrell Bank Observatory. ...

dog days

(Encyclopedia)dog days, name for the most sultry period of summer, from about July 3 to Aug. 11. Named in early times by observers in countries bordering the Mediterranean, the period was reckoned as extending from...

Young, Charles Augustus

(Encyclopedia)Young, Charles Augustus, 1834–1908, American astronomer, b. Hanover, N.H., grad. Dartmouth, 1853. He discovered the reversing layer of the solar atmosphere and proved the gaseous nature of the sun's...

retrograde motion

(Encyclopedia)retrograde motion, in astronomy, real or apparent movement of a planet, dwarf planet, moon, asteroid, or comet from east to west relative to the fixed stars. The most common direction of motion in the...

Tellus

(Encyclopedia)Tellus tĕlˈəs [key], in Roman religion, earth goddess; also called Terra Mater. As a goddess of fertility, she was worshiped at festivals held in January (in conjunction with Ceres) and in April. T...

Stratospheric Observatory for Infrared Astronomy

(Encyclopedia)Stratospheric Observatory for Infrared Astronomy: see infrared astronomy. ...