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THE VULGAR AND PHOTOMETRIC SCALE.
1. NORTHERN STARS.
II. SYNOPTIC TABLE OF THE ELEMENTS OF THE PLANETARY SYSTEM.
Name of Body.
Mean Distance from the Mean Sidereal Period in Mean
Excentricity in parts of
Inclination of Orbit to the
Longitude of the Ascending
ELEMENTS OF THE PLANETARY SYSTEM.
Longitude of the
Name of Body.
at Epoch of the Elements in M.T.
minator of frac. | Diameter in S Greenwich (G.) 2 Berlin (B.)
tion, the Sun Miles.
1801. Jan. 1. Ob G.
Do. 1848. Jan. 1. Ob G.
Note.---The elements of the orbits of Mercury, Venus, the Earth, Mars, Jupiter, Saturn, and Uranus, are those given by the late F. Baily, Esq., in his “ Astronomical Tables and Formulæ," and are the same with those which form the basis of Delambre's tables, embodying the formulæ of Laplace. The elements of Uranus and Neptune can only be regarded as provisional; those of the former requiring considerable corrections, necessitated by the discovery of Neptune, but which, not being yet finally ascertained, by reason of the uncertainty still attending on the mass and elements of the latter planet, it was thought better to leave the old elements untouched than to give an imperfect rectification of them,
The masses of the planets are those most recently adopted by Encke (Ast. Nachr. No. 443.), on mature consideration of all the authorities, that of Neptune excepted, which is Prof. Pierce's determination from Bond's and Lassell's observation of the satellite discovered by the latter. The densities are Hansen's (A. N. 443.).
The elements of Vesta, Juno, Ceres, and Pallas, are the osculating elements for 1850, computed by Encke (A. N. 636.). [Those of Flora are from the computations of Brunnow (A. N. 645.); of Victoria, Villarceaux (A. N. 741.); of Iris, Schubers (A. N. 730.); of Metis, Wolfers (A. N. 764.); of Hebe, Luther (A. N. 721.); of Parthenope, Galen (A. N. 757.); of Astræa, D'Arrest (A. N. 626.); of Egeria, D'Arrest (A. N. 749.); of Irene, Vogel and Bumker (A. N. 765.); and of Hygeia, Santini (A. N. 702.).
Of these last-mentioned small planets, Hygeia, Parthenope, and Egeria were discovered by Dr. Gasparis, at Naples, on April 12. 1849, May 11. and Nov. 2. 1850, respectively; Iris, Flora, Victoria, and Irene, by Mr. Hind, on Aug. 13. and Oct. 18. 1847, Sept. 13. 1850, and May 19. 1851, respectively. The elements of the recently-discovered small planets may undergo material corrections from further observation. Irene has a blue colour and a faint nebulous envelope. The orbits of Astræa and Hygeia approach at one point (their common node) within 0.006 of the radius of the earth's orbit. It will not be long before the planets themselves come within that proximity to each other (A. N. 752.). Victoria and Astræa are subject to variations of brightness, which indicate rotations on their axes, and dark spots (A. N. 760.). D'Arrest (A. N. 752.) remarks that a relation subsists between the excentricities of the orbits of the small planets, and the inclinations of the planes in which they lie to the sun's equator, the more excentric orbits being the more inclined. While these sheets pass through the press, another, yet unnamed, is announced by M. de Gasparis. ]
SYNOPTIC TABLE OF THE ELEMENTS OF THE ORBITS
1. The Moon.
591-96435000 Mean sidereal revolution
274.321661418 Mean synodical ditto.
294.530588715 Excentricity of orbit
0·054844200 Mean revolution of nodes
67934.391080 Mean revolution of apogee
• 32324.575343 Mean longitude of node at epoch
13° 53' 1711.7 Mean longitude of perigee at do.
266 10 7 5 Mean inclination of orbit
5 8 47 9 Mean longitude of moon at epoch.
118 17 8.3 Mass, that of earth being 1,
0.011399 Diameter in miles
21 53 Density, that of the earth being 1, :
0'56 57 • The distances are expressed in equatorial radii of the primaries. The epoch is Jan. 1. 1801, unless otherwise expressed. The periods, &c. are expressed in mean solar days.