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NGC 6204
NGC 6204 is an open cluster in the constellation Ara (constellation), Ara, lying close to the galactic equator. It is 3,540 ly (1,085 pc) distant from Earth. The cluster was discovered on 13 May 1826 by British astronomer James Dunlop. References Further reading * Carraro, Giovanni; Munari, Ulisse (2004): ''A multicolour CCD photometric study of the open clusters NGC 2866, Pismis 19, Westerlund 2, ESO96-SC04, NGC 5617 and NGC 6204''; Monthly Notices of the Royal Astronomical Society 347 (2), S. 625–631 External links * http://seds.org/* Image NGC 6204 {{DEFAULTSORT:NGC 6204 Open clusters, NGC 6204 NGC objects, 6204 Ara (constellation) Astronomical objects discovered in 1826 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
