proper motionn.

Brit.

/ˌprɒpə ˈməʊʃn/, U.S.

/ˌprɑpər ˈmoʊʃ(ə)n/

Origin: Formed within English, by compounding; apparently originally modelled on a Spanish lexical item. Etymons: proper adj., motion n.

Etymology: < proper adj. + motion n., apparently originally after Spanish propio movimiento (1556 as proprio mouimento in the passage translated in quot. 1561). Compare post-classical Latin motus proprius (1611 or earlier in this sense), Middle French propre mouvement (1426; French mouvement propre).

Astronomy.

Originally: motion intrinsic to a celestial object. In later use: spec. the apparent angular motion of a star or other object across the celestial sphere caused by the relative motion of the object and the sun.The discovery of the proper motion of the fixed stars is generally attributed to Edmund Halley (1718); it is usually expressed in seconds of arc per year.

ΘΚΠ

the world > the universe > star > stellar motion > [noun]

proper motion1561

star drift1829

star stream1844

motus peculiaris1890

star streaming1905

drift1906

1561 R. Eden tr. M. Cortés Arte Nauigation i. viii. f. x The Moone..by her proper motion [Sp. proprio mouimento] geueth her turne from the Weste to the Easte, in .xxvii. dayes, and seuen houres, with .xlv. minutes.

1604 E. Grimeston tr. J. de Acosta Nat. & Morall Hist. Indies iii. vii. 141 This proper and equal motion [Sp. mouimiento proprio y vniforme] of the heaven.

1628 R. Burton Anat. Melancholy (ed. 3) ii. ii. iii. 239 Saturne in 30 yeares absolues his sole and proper motion.

1701 W. Holder Disc. Time (ed. 2) vi. 58 The Moon... Her Periodic month, or Month of Peragration, which chiefly respects her own proper Motion, or place in the Zodiac.

1773 Philos. Trans. (Royal Soc.) 63 93 It appears that some of the fixed stars have a proper motion, independent of any motion hitherto known in our own system.

1870 Proc. Royal Soc. 1869–70 18 169 When the proper motions are indicated in maps,..the star-drift..becomes very evident.

1929 A. S. Eddington Nature of Physical World viii. 168 Groups of stars are found which move across the sky with common proper motion; these must have had a single origin and cannot have been formed by casual collisions.

1989 I. Asimov Nemesis (1990) 34 I do have a few older pictures of that part of the sky and I could detect an appreciable proper motion.

This entry has been updated (OED Third Edition, June 2007; most recently modified version published online March 2022).

单词	proper motion
释义	proper motionn. Brit. /ˌprɒpə ˈməʊʃn/, U.S. /ˌprɑpər ˈmoʊʃ(ə)n/ Origin: Formed within English, by compounding; apparently originally modelled on a Spanish lexical item. Etymons: proper adj., motion n. Etymology: < proper adj. + motion n., apparently originally after Spanish propio movimiento (1556 as proprio mouimento in the passage translated in quot. 1561). Compare post-classical Latin motus proprius (1611 or earlier in this sense), Middle French propre mouvement (1426; French mouvement propre). Astronomy. Originally: motion intrinsic to a celestial object. In later use: spec. the apparent angular motion of a star or other object across the celestial sphere caused by the relative motion of the object and the sun.The discovery of the proper motion of the fixed stars is generally attributed to Edmund Halley (1718); it is usually expressed in seconds of arc per year. ΘΚΠ the world > the universe > star > stellar motion > [noun] proper motion1561 star drift1829 star stream1844 motus peculiaris1890 star streaming1905 drift1906 1561 R. Eden tr. M. Cortés Arte Nauigation i. viii. f. x The Moone..by her proper motion [Sp. proprio mouimento] geueth her turne from the Weste to the Easte, in .xxvii. dayes, and seuen houres, with .xlv. minutes. 1604 E. Grimeston tr. J. de Acosta Nat. & Morall Hist. Indies iii. vii. 141 This proper and equal motion [Sp. mouimiento proprio y vniforme] of the heaven. 1628 R. Burton Anat. Melancholy (ed. 3) ii. ii. iii. 239 Saturne in 30 yeares absolues his sole and proper motion. 1701 W. Holder Disc. Time (ed. 2) vi. 58 The Moon... Her Periodic month, or Month of Peragration, which chiefly respects her own proper Motion, or place in the Zodiac. 1773 Philos. Trans. (Royal Soc.) 63 93 It appears that some of the fixed stars have a proper motion, independent of any motion hitherto known in our own system. 1870 Proc. Royal Soc. 1869–70 18 169 When the proper motions are indicated in maps,..the star-drift..becomes very evident. 1929 A. S. Eddington Nature of Physical World viii. 168 Groups of stars are found which move across the sky with common proper motion; these must have had a single origin and cannot have been formed by casual collisions. 1989 I. Asimov Nemesis (1990) 34 I do have a few older pictures of that part of the sky and I could detect an appreciable proper motion. This entry has been updated (OED Third Edition, June 2007; most recently modified version published online March 2022). < n.1561
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