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Pasiphaë, in astronomy

(Encyclopedia)Pasiphaë pəsĭfˈəēˌ [key], in astronomy, one of the 39 known moons, or natural satellites, of Jupiter. ...

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 ...

Vulcan, in astronomy

(Encyclopedia)Vulcan, in astronomy, hypothetical planet whose existence was proposed by Le Verrier to explain part of the advance of the perihelion of Mercury, not all of which could be accounted for by gravitation...

Regulus, in astronomy

(Encyclopedia)Regulus rĕgˈyələs [key], brightest star in the constellation Leo; Bayer designation Alpha Leonis; 1992 position R.A. 10h08m, Dec. +12°00′. A bluish-white main-sequence star of spectral class B7...

Taurus, in astronomy

(Encyclopedia)Taurus [Lat.,= the bull], in astronomy, constellation NW of Orion and lying on the ecliptic (the sun's apparent path through the heavens) between Gemini and Aries; it is one of the constellations of t...

Tethys , in astronomy

(Encyclopedia)Tethys tēˈthĭs [key], in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn III (or S3), Tethys is 659 mi (1060 km) in diameter, orbits Saturn at a mean dista...

Triton , in astronomy

(Encyclopedia)Triton trītˈən [key], in astronomy, innermost and largest of the eight known moons, or natural satellites, of Neptune. ...

Uranus , in astronomy

(Encyclopedia)Uranus yo͝orāˈnəs, yo͝orˈə– [key], in astronomy, 7th planet from the sun, at a mean distance of 1.78 billion mi (2.87 billion km), with an orbit lying between those of Saturn and Neptune; its...

Saturn, in astronomy

(Encyclopedia)CE5 Saturn and its ring system as seen from Earth Saturn, in astronomy, 6th planet from the sun. Saturn has 82 confirmed natural satellites, many of which have not been named. Five of the discov...

Pleiades, in astronomy

(Encyclopedia)Pleiades plēˈədēz, plīˈ– [key], in astronomy, famous open star cluster in the constellation Taurus; cataloged as M45. The cluster consists of some 500 stars, has a diameter of 35 light-years, ...