| 释义 |
galactic, a.|gəˈlæktɪk|
[ad. Gr. γαλακτικός, f. γαλακτ-, γάλα, milk. Cf. F. galactique.]
1. Of or pertaining to milk. = lactic.
1844Hoblyn Dict. Med., Galactic acid, Lactic acid, the acid of milk. 1854in Mayne; and in mod. Dicts.
2. Astron. Of or pertaining to the Galaxy or Milky Way; of or pertaining to another galaxy or to galaxies in general; galactic belt, the Milky Way; galactic circle (see quot. 1893); galactic concentration, the increase in the number of stars from the galactic poles to the galactic equator; galactic co-ordinates, spherical co-ordinates used in astronomy, comprising galactic latitude and longitude; galactic equator, a great circle passing as nearly as possible through the middle of the Milky Way; galactic latitude, latitude measured from the galactic equator; galactic longitude, longitude measured from some reference point on the galactic equator, usu. defined either by the direction of the centre of the galaxy or by the intersection of the galactic and the celestial equators; galactic plane, the plane defined by the galactic equator; galactic poles: the two opposite points of the heavens, situated at 90° from the galactic circle; galactic system, the galaxy containing the sun and most of the visible stars; galactic zone = galactic belt.
1839Bailey Festus xix. (1848) 224 Her brow [grew] Brighter with thought, as with galactic light Mid heaven when clearest. 1849J. F. W. Herschel Outl. Astron. xv. 534 The following table, expressing the densities of the stars at the respective distances, 1, 2, 3, &c., from the galactic plane. Ibid. 535 The law of the visible distribution of stars over the southern galactic hemisphere, or that half of the celestial surface which has the south galactic pole for its center. 1849Ibid. (ed. 10) § 793 The density of star-light..is least in the pole of the Galactic circle. 1856Chamb. Jrnl. V. 397 The phalanx of star⁓hosts made galactic or milky by distance. 1878S. Newcomb Pop. Astron. iv. 417 Telescopic stars..are least numerous in the regions most distant from the galactic belt. 1888C. A. Young Text-bk. Gen. Astron. xxi. 510 The ‘galactic plane’ ‘is to sidereal what the ecliptic is to planetary astronomy, a plane of ultimate reference, the ground plan of the sidereal system’. 1890A. M. Clerke Syst. Stars xxiii. 355 The bright spaces of the galactic zone are commonly surrounded and set off by dark winding channels. Ibid. 359 A regular progression of density from the galactic poles to the galactic equator. Ibid., Two or three hundred ‘beginning, or gathering clusters’, might be pointed out in the galactic system. 1893Gore Astron. Gloss., Galactic Circle, a term applied to the mean or centre line of the Galaxy, or Milky Way zone. 1906Rep. Brit. Assoc. 1905 260 Mean values were computed for different galactic latitudes by combining the results of regions at equal distances from the Milky Way. 1914A. S. Eddington Stellar Movements viii. 165 The stars with proper motions greater than 10{pp} per century show no galactic concentration; they are all comparatively near to us. Ibid. ix. 196 A systematic dependence on galactic longitude in some of the zones. 1926Encycl. Brit. I. 252/1 In plan the system is elongated with its axis in galactic longitude 325°. 1930R. H. Baker Astron. xi. 442 The galactic equator is the great circle halfway between the galactic poles. 1931W. M. Smart Text-bk. Spherical Astron. xi. 276 The galactic co-ordinates of S. 1936E. Hubble Realm Nebulæ vi. 125 The galactic system is a member of a typical, small group of nebulæ which is isolated in the general field. 1965J. B. Sykes tr. Ogorodnikov's Dynamics Stellar Syst. i. 25 The choice of any particular coordinate system is a matter of convenience. In stellar astronomy the most frequently used is that of galactic coordinates, defined by the galactic equator and the galactic poles. 1971Nature 18 June 437/1 Results from sounding rocket experiments..have revealed the existence of cosmic X-ray sources at high galactic latitude. |