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: http://www.sao.ru/fetch/HL/leda/param/celpos.html
Дата изменения: Mon Dec 23 18:23:59 2013 Дата индексирования: Fri Feb 28 18:24:27 2014 Кодировка: Поисковые слова: р п р п р п р п р п р п р п р п р п р п р п р п р п |
The original measurements are now accessible from the current interface.
For the stars, the position is always at epoch 2000, whatever J2000 or B1950
coordinates are printed. This is because proper motions are not stored
in the database. For a correct astrometry of stars, en advice to use Simbad.
System | Description |
---|---|
B1950 | Equatorial coordinates, Besselian, Equinox 1950.0, Epoch 2000.0 |
J2000 | Equatorial coordinates, Julian, Equinox 2000.0, Epoch 2000.0 |
G | Galactic coordinates in the reference frame called "new" system, adopted by IAU in 1958. Galactic pole at B124900.0+272400, node at ra=282.25,l=33 deg (inclination 62.6 deg). The B1950 north celestial pole is at l=123, b=27.4 deg. |
SG | Supergalactic coordinates.
Supergalactic equator is conceptually defined by the plane
of the local (Virgo-Hydra-Centaurus) supercluster, and the
origin of supergalactic longitude is at the intersection
of the supergalactic and galactic planes. See the definition
in RC2 (de Vaucouleurs et al. 1976) and RC3 (de Vaucouleurs et al. 1991):
North SG pole at l=47.37 deg, b=6.32 deg. Node at
l=137.37, sgl=0 (inclination 83.68 deg). Note: The position of the SG node reported in RC2 (137.29 deg) differs from RC3 (137.37 deg; see page 12, the difference is mentioned but not commented). |
f_astrom |
definition |
---|---|
-1 |
precision about 0.1 arcsec |
0 |
1 arcsec |
1 |
10 arcsec |
2 |
100 arcsec (1 arcmin) |
3 |
1000 arcsec (10 arcmin) |
In SQL search constraints may be put on the following parameters
Parameter | Description |
---|---|
al2000 | Right ascension J2000 |
de2000 | Declination J2000 |
al1950 | Right ascension B1950 |
de1950 | Declination B1950 |
l2 | Galactic longitude |
b2 | Galactic latitude |
sgl | Super Galactic longitude |
sgb | Super Galactic latitude |
f_astrom | Precision flag on the celestial position |
HyperLeda | Questions: prugniel@obs.univ-lyon1.fr |