Etymology
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Urania 
name of the Muse of astronomy and celestial forces, from Latin Urania, from Greek Ourania, fem. of ouranios, literally "heavenly," from ouranos (see Uranus).
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albedo (n.)
in astronomy "proportion of light reflected from a surface," 1859, from scientific use of Latin albedo "whiteness," from albus "white" (see alb).
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Almagest (n.)
late 14c., title of a treatise on astronomy by Claudius Ptolemy of Alexandria, from Old French almageste (13c.), from Arabic al majisti, from al "the" + Greek megiste "the greatest (composition)," from fem. of megistos, superlative of megas "great" (from PIE root *meg- "great").

Originally titled in Greek Mathematike syntaxis ("Mathematical Composition"), commonly called Megale syntaxis "Great Composition" (Greek megale is the fem. of megas); Arab translators in their admiration altered this. Extended in Middle English to other works on astrology or astronomy,
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protostar (n.)

in astronomy, "contracting mass of gas considered as an early stage in the formation of a star," by 1951, from proto- + star (n.).

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sunspot (n.)
also sun-spot, 1849, in astronomy, from sun (n.) + spot (n.). Earlier "a spot on the skin caused by exposure to the sun" (1818).
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quartile (n.)

mid-15c., originally in astrology and astronomy in the phrase quartile aspect in reference to celestial bodies when 90 degrees apart in longitude; see quartile (adj.). In statistics, from 1879.

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mathematical (adj.)

"of, pertaining to, or of the nature of mathematics," early 15c., from Medieval Latin mathematicus "of or belonging to mathematics," from Latin mathematica (see mathematic) + -al (1). Also, by 1765, "pertaining to the quadrivium," comprising arithmetic, geometry, astronomy, and music. It also could include optics. Related: Mathematically.

The four mathematical arts are arithmetic, geometry, music, and astronomy; these anciently were termed the quadrivium, or fourfold way of knowledge. [Sir John Hawkins, "A General History of the Science and Practice of Music," Sir John Hawkins, 1776]
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sunglasses (n.)
glasses with darkened lenses to protect one's eyes while observing the sun, also sun-glasses, 1878, from sun (n.) + glasses. In popular (non-astronomy) use from 1916. Earlier sunglass (1804) meant a burning glass.
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octant (n.)

instrument for making angular measurements in navigation or astronomy, 1731, from Late Latin octans "the eighth part," from octo "eight" (see octa-) on analogy of quadrant. In geometry, "the eighth part of a circle," by 1750.

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antecedence (n.)
1650s, "fact or act of coming before (another or others) in time, place, or order," from Latin antecedens "a going before" (see antecedent). From 1660s in specific sense in astronomy, "apparent contrary motion of a planet" (from east to west). Related: Antecedency (1590s).
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