SYNOPTICAL TABLES.
N.B.— The epoch for the elements in the following tables is, unless otherwise stated, the beginning of the present century.
THE SOLAR SYSTEM.
LAWS OF MOTION.
1. Every body continues in a state of rest or uniform rectilineal motion, unless affected by some mechanical force.
2. Every change of motion is proportionate to the force impressed, and is made in the direction of that force.
3. Action must always be equal and contrary to reaction, or the actions of two bodies on each other are always equal and directed to contrary sides.
KEPLER'S LAWS.
1. The orbit of each planet is an ellipse, of which the sun occupies one of the foci.
2. The areas described about the sun by the radius vector of the planet are proportional to the times employed in describing them.
3. The squares of the times of the sidereal revolutions of the planets are to each other as the cubes of their mean distances from the sun.
LAW OF GRAVITATION.
Any two bodies attract each other with a force proportional directly to the quantity of matter they contain, and inversely to the square of their distances.
ELEMENTS OF ELLIPTICAL MOTION.
1. The mean distance of the planet from the sun, or half the major axis of the orbit.
2. The duration of a mean sidereal revolution of a planet.
3. The mean longitude of the planet at a given epoch.
4. The longitude of the perihelion at a given epoch.
5. The inclination of the orbit to the ecliptic at a given epoch.
6. The longitude of the nodes at a given epoch.
7. The eccentricity of the orbit.
SECULAR VARIATIONS IN ORBIT.
The position of the apsides.
The inclination of the orbit to the ecliptic.
The position of the nodes.
The amount of eccentricity.
NUMBER OF BODIES OF SOLAR SYSTEM.
Principal planets, including Vulcan, | 9 |
Asteroids, (1861,) | 71 |
Satellites, | 18 |
Periodic comets, | 27 |
Planetary rings, | 3 |
Zones of asteroids, probably | 3 |
LAWS OF LIGHT.
Intensity inversely proportional to the square of the distance from source. | |
Velocity in miles, per second, | 192,000 |
BODE'S LAW OF PLANETARY DISTANCES.
The intervals between the orbit of Mercury and the other planetary orbits go on doubling as we recede from the sun.
The first of the following series represents the distances from the orbit of Mercury; the second, by adding 4 as the distance of Mercury from the Sun, represents the planetary distances from the centre of the system:—
Mer. | Ven. | Earth. | Mars. | Ast. | Jup. | Sat. | Uran. | Nep. | |
Distance from Mercury, | 0 | 3 | 6 | 12 | 24 | 48 | 96 | 192 | 384 |
4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | |
— | — | — | — | — | — | —— | —— | —— | |
Distance from Sun, | 4 | 7 | 10 | 16 | 28 | 52 | 100 | 196 | 388 |
Actual distances. | 3.9 | 7.3 | 10 | 15.2 | 27.4 | 52 | 95.4 | 192 | 300 |
Average density of planets exterior to asteroids (water =1), | 1.07 |
Average density of interior planets, | 5.33 |
Proportion of average diameter of interior planets to that of exterior, | 1-10th |
Average rotation of exterior planets, in hours, nearly | 10 |
Average rotation of interior planets, nearly | 24 |
Number of satellites of exterior planets, | 18 |
Number of satellites of |interior planets, | 1 |
KIRKWOOD'S LAW.
The square of the number of times that each planet rotates during one revolution in its orbit is proportional to the cube of the diameter of its sphere of attraction.
The sphere of attraction is that within which the attraction of one planet is greater than that of the next interior or exterior planet.
Name of Body. | Volume. | Density. | Light and Heat. | Gravity. | Time of Rotation. | Distance from Sun. | |
h. | m. | ||||||
Sun | 1415225 | .250 | ... | 28.36 | 607 | 48 | ... |
Vulcan | .0035 | ... | 30.32 | ... | ... | .19 | |
Mercury | .0595 | 1.225 | 7.58 | 0.48 | 24 | 6 | .39 |
Venus | .9960 | .908 | 1.91 | 0.9 | 23 | 21 | .73 |
Earth | 1.0 | 1.0 | 1.0 | 1.0 | 23 | 56 | 1.00 |
Mars | .1364 | .972 | 0.43 | 0.49 | 24 | 37 | 1.52 |
Asteroids | ... | ... | ... | ... | ... | 2.74 | |
Jupiter | 1491.0 | .227 | .0372 | 2.45 | 9 | 55 | 5.20 |
Saturn | 772.0 | .131 | .0111 | 1.09 | 10 | 29 | 9.54 |
Uranus | 86.5 | .167 | .0026 | 0.76 | ... | 19.18 | |
Neptune | 76.6 | .321 | .0011 | 1.36 | ... | 30.03 |
Volume (Earth's = 1), | 1,415,225 |
Mass (Earth's = 1), | 354,936 |
Density (Earth's = 1), | 0.2543 |
Diameter (Earth's = 1), | 111.454 |
Diameter in miles, | 882,646 |
Diameterapparent, mean, | 32′ 12″.6 |
Gravity at equator (Earth's = 1), | 28 |
In one second of time bodies fall, in feet, | 335 |
Period of rotation in days, | 25.5 |
Zone of maximum spots north from the equator, | 11°—15° |
Usual limit of spots from the equator, | 33° |
Period of maximum number of spots, in years, | 10 |
Diameter of maximum spot (Sun's = 1), | 0.05 |
Breadth of zone of drift, at equator, direction of rotation, | 30° |
Breadth of zone of drift,„ in each hemisphere, opposite direction, | 30° |
Light of the Sun (light of star of 1st Mag. = 1), | 108,000,000,000 |
Intensity of Sun's light (electric light = 1), | 4 |
Intensity of Sun's light : (wax candle = 1), | 15,000 |
Heat of each square foot of surface, mechanical effect, in horse-power, | 7,000 |
Heat of each square foot of surface, equal the combustion of cwts. of coals per hour, | 13.5 |
Heat of each square foot of surface, equal 5 lbs. matter falling with velocity per second, in miles, | 390 |
Heat at centre of disc (heat at border = 1), | 2 |
Diameter of largest spots, in miles, | 50,000 |
Number of strata in atmosphere, | 4 |
Spots seen to rotate on their axis (in days), about | 18 |
Heat equivalent to loss of mechanical force by Mercury falling into Sun (a year's heat of Sun = 1), | 3 |
Velocity of bodies near the Sun (miles per second), about | 400 |
Point in Hercules to which the Sun is advancing, declination 35° N., right ascension, | 250° |
Velocity of Sun in its orbits, miles per year, | 150,000,000 |
Mean distance from the earth in miles, | 95,000,000 |
Mean distance from the earth in miles, (Earth's radius = 1), | 23,984 |
Light of Sun reaches the Earth in | 8m |
Inclination of axis to ecliptic, | 82° 40′ 0″ |
Time of passing over one degree of mean longitude, | 24h 20m 58s |
Eccentricity of orbit (semi-axis major = 1), | .01685 |
Mean longitude, | 280° 34′ 10″ |
Longitude of the perigee, | 270° 30′ 5″ |
Greatest equation of centre, | 1° 55′ 27″ |
Motion of perigee in a year, | 1′ 1″ |
Volume (Earth's = 1), | 0.06 |
Mass (Earth's = 1), | 0.0769 |
Density (Earth's = 1), | 1.225 |
Diameter (Earth's = 1), | 0.389 |
in miles, | 3,200 |
Diameter apparent mean, | 6″.9 |
Gravity (Earth's = 1), | 0.48 |
In one second of time bodies fall, in feet, | 7.07 |
Period of rotation, | 24h. 5m. 28s. |
Light and heat received at perihelion (Earth's =1), | 10.58 |
Light and heat received„ at aphelion, | 4.59 |
Light and heat received„ at mean distance. | 7.58 |
Least elongation from Sun, | 16° 12′ |
Greatest elongation. | 28° 48′ |
Height of mountain at southern horn in miles. | 12 |
Height of same (radius of Mercury = 1), | .008 |
Mean distance from the Sun in miles, | 36,725,000 |
Mean distance from the sun (Earth's distance =1 | .3870084 |
Greatest distance (Earth's distance = 1), | .40666927 |
Least distance (Earth's distance = 1), | .3075041 |
Eccentricity (semi-major axis = 1), | .2056178 |
Sidereal revolution in days, | 87.9692824 |
Synodical revoultion in days, | 115.877 |
Longitude of perihelion, | 74° 57′ 21″ |
Longitude of ascending node, | 46° 23′ 55″ |
Inclination of orbit to ecliptic, | 7° 0′ 13″ |
Mean daily motion in orbit, | 2° 11′ 23″ |
Mean daily motion in orbit, miles per hour, | 109,360 |
Inclination of bands to the planet's orbit, | 70° |
Days in falling to the Sun, | 15.6 |
Volume (Earth's = 1), | 0.996 |
Mass (Earth's = 1), | 0.908 |
Density (Earth's = 1), | 0.923 |
Diameter (Earth's = 1), | 0.975 |
Diameter in miles, | 7700 |
{{ditto bar|Apparent, mean, | 16″.9 |
Gravity (Earth's = 1), | 0.98 |
In one second of time bodies fall, in feet, | 14.5 |
Period of rotation, | 23h. 21m. 7s. |
Light and heat (Earth's = 1), | 1.91 |
Least elongation, | 45° |
Greatest elongation. | 47° 12′ |
Greatest height of mountains in miles. | 27 |
Mean distance from the Sun in miles, | 68,000,000 |
Mean distance from the Sun (Earth's = 1), | 0.7233316 |
Eccentricity (semi-major axis = 1), | 0.00686074 |
Sidereal revolution in days. | 224d. 6h. 49m. 8s. |
Mean synodical revolution in days, | 583.920 |
Longitude of perihelion. | 128° 43′ 53″ |
Longitude of ascending node. | 74° 54′ 12″ |
Inclination of orbit to ecliptic, | 3° 23′ 28″ |
Mean daily motion in orbit, | 1° 36′ 7″ |
Mean daily motion in orbit, miles per hour | 80,000 |
Inclination of axis to ecliptic. | Uncertain |
Next transit of Venus on December 8, 1874. | |
Days in falling to the Sun, | 39.7 |
Volume, | 1.000 |
Mass (Sun's = 1), | 0.0000028173 |
Density (water = 1), | 5.6747 |
Diameter, mean, in miles, | 7916 |
Diameter polar, in miles, | 7898 |
Diameter equatorial, in miles, | 7924 |
Circumference in miles, | 25,000 |
In one second of time bodies fall, latitude of London, in feet, | 16.835 |
Centrifugal force at equator (gravity = 1), | 0.00346 |
Times rotation requires to be increased to neutralise gravity at equator, | 17 |
Period of rotation in sidereal hours, | 24 |
Length of a mean solar day in sidereal time, | 24h. 3m.- 56s..55 |
Length of a sidereal day in mean solar time, | 23h. 56m. 4s.09 |
Daily acceleration of sidereal time in mean solar time, | 3m. 55s..09 |
Greatest difference between the mean and apparent solar time, | 16m. 16s. |
Greatest height of mountains in miles, | 5 |
Axis of the poles (axis of diameter of equator = 305), | 304 |
Greatest depth of ocean in miles, | 9 |
Mean distance from the Sun (Earth's radius = 1), | 23,984 |
Mean distance from the Sun in miles, | 95,000,000 |
Distance at perihelion (mean distance = 1), | .9832 |
distance at aphelion (mean distance = 1), . | 1.0168 |
Eccentricity (semi-major axis = 1), | 0.016783568 |
Sidereal revolution in mean solar days. | 365d. 6h. 9m. 9s..6 |
Anomalistic revolution in mean solar days. | 365d. 6h. 13m. 49s. |
Tropical revolution in mean solar days, | 365d. 5h. 48m. 49s..7 |
Interval between vernal and autumnal equinoxes, | 186d. 11h. 34m. |
Interval between autumnal and vernal equinoxes, | 178d. 18h. 7m. |
The latter shorter than the former, by | 7d. 17h. 27s. |
Time required by Sun's light to reach the Earth, | 8m. 13s..3 |
Constant of aberration, | 20″.36 |
Average horizontal refraction, | 33′ 6 |
Average refraction at 45° of altitude, | 57″ |
Height of atmosphere in miles, | 40 |
Height of atmosphere, supposing no decrease of density, | 5 |
Greatest height at which clouds exist, in miles, | 10 |
Distance to which a body must be projected horizontally to revolve as a satellite, in miles, | 4.35 |
Action of the Moon on the tides (Sun's = 1), | 3 |
Daily mean retardation of high-water, | 50m. 28s. |
Mean retardation in syzygies, | 39m. 12s. |
Mean retardation in quadratures, | 1h. 14n. 58s. |
Revolution of the Sun's perigee in mean solar days, | 7,645,793 |
Mean longitude of perigee, | 100° 30′10″ |
Earth's motion in perihelion in a mean solar day, | 1° 1′ 9″ |
Mean motion in a mean solar day, | 59′ 8″.33 |
Mean Motion in a sidereal day, | 59′ 58″.64 |
Motion in aphelion in a mean solar day, | 57′ 11″.50 |
Mean longitude of perihelion, | 90° 30′ 5″ |
Annual motion of perihelion, | 11″.8 |
Same referred to the ecliptic, | 1° l″.9 |
Tropical revolution of perihelion in mean solar years, | 20,984 |
Obliquity of the ecliptic, | 23° 27′ 56″.5 |
Annual diminution of obliquity, | 0″.457 |
Limit of variation, | 2° 42′ |
Nutation lunar, semi-axis major of the ellipse, | 9″.4 |
Nutation solar, maximum, | 0″.493 |
Luni-solar precession of the equinoxes, annual, | 50″.41 |
Planetary precession, | 0″.31 |
General precession, | 50″.11 |
Complete revolution of the equinoxes in years, | 25,868 |
Lunar nutation in longitude, | 17″.579 |
Solar nutation in longitude, | 1″.137 |
Rate per minute at which equator rotates, in miles, | 17 |
Rate per second of her velocity in orbit, in miles, | 20 |
Days in falling to the Sun, | 64.6 |
Volume (Earth's = 1), | 1-49th |
Mass (Earth's = 1), . | 1-80th |
Density (Earth's = 1), | 0.615 |
Density (water = 1), | 3.37 |
Diameter (Earth's = 1), | 0.264 |
Diameter in miles, | 2164.6 |
Diameter apparent, mean, | 31′ 7″ |
Diameter apparent minimum, | 29′ 21″.9 |
Diameter maximum. | 33' 3″.1 |
Gravity at surface (Earth's = 1), | 1-6th |
In one second of time bodies fall, in feet. | 2-6 |
Centre of figure nearer the earth than centre of gravity, in miles, | 33 |
Elevation of highest mountain in the Moon (Doerfel), in feet, | 24,945 |
Elevation of highest mountain (Moon's diam. = 1), | 1-454th |
Elevation of highest mountain on the Earth, in feet, | 28,180 |
Elevation of highest mountain(Earth's diam. = 1) | 1-1480th |
Greatest depth of craters below the general surface in feet, | 17,000 |
Greatest diameter of craters, or cavities with or without raised walls, in miles, | 55 |
Greatest diameter„ of walled plains, in miles, | 150 |
Greatest height of central cone, in feet. | 5000 |
Longest bright ray (Tycho), | 1800 |
Rills, greatest length in miles, | 150 |
Rills greatest breadth in feet, | 6000 |
Rills number, | 90 |
Number of mountains higner than Mont Blanc, | 28 |
Length of the range of the Lunar Appenines, in miles, | 200 |
Proportion of surface covered with craters, | 3-5ths |
Tycho, height in feet, | 20,180 |
Tycho diameter in miles, | 54 |
Tycho longest ray, | 1800 |
Tycho number of bright rays, about | 54 |
Diameter of Mt. Vesuvius in feet, | 500 |
Height of Pico, a bright isolated peak, in feet, | 7060 |
Disc of the Earth, as seen from Moon (Moon's disc = 1), | 14 |
Proportion of the Moon's surface alternately hid and visible, | 1-7th |
Light of the Moon at mean distance (Sun's = 1) . | 1-800000th |
Heat of the Moon (heat of a candle at distance of 15 feet = 1), | 1-3d |
Velocity of projection necessary for a lunar body to reach the Earth, feet, per second. | 8200 |
Distance in miles of Moon's surface under a magnifying power of 1000, | 240 |
A circle of one second in diameter as seen from the Earth, in square miles. | 1 |
Limit of vision in the case of a circle or square, | 60″ |
Limits of vision in an indefinitely extended object, | 6″ |
Magnifying power required to see an embankment, 6 feet broad, | 6000 |
Highest power attained with distinct vision, | 2000 |
Maximum limit of atmosphere (one inch of mercury = 1), | 1-45th |
Maximum limit of refraction (at surface of earth = 1), | 1-1980th |
Maximum limit of horizontal refraction at Moon, | 1" |
Eclipses, annual number, minimum (only solar), | 2 |
Eclipses, annual number. maximum, | 7 |
Eclipses, maximum of annular phase, | 12m. 24s. |
Eclipses, totality (solar), | 7m. 58s. |
Eclipses, length of Earth's shadow (distance of moon = 1), | 3.5 |
Eclipses, period of recurrence in same order and magnitude in years, | 18-6 |
Eclipses, total number in period (29 lunar, 41 solar), about | 70 |
Mean distance from the Earth (Earth's radius = 1), | 60.2734 |
Mean distance from the Earth in miles | 237,000 |
Period, in days, of rotation, | 27.3215824 |
Period, in days, revolution, mean tropical, | 27.3215824 |
Period, in days, revolution, mean sidereal, | 27.321661 |
Period, in days, revolution, mean synodical, | 29.530588 |
Period, in days, revolution, mean anomalistic, | 27h. 18m. 37s. |
Period, in days, mean revolution of node, | 6793.39108 |
Period, in days, mean revolution of apsides. | 3232.575343 |
Motion eastwards of line of apsides in each lunation. | 3° |
Mean longitude of Moon, | 118° 17′ 8″ |
Mean longitude node, | 13° 53′ 17″.7 |
Mean longitude perigee | 266° 10′ 7″.5 |
Mean inclination of orbit to ecliptic, | 5° 8′ 47″.9 |
Mean inclination maximum variation. | 5° 8′ 47″.1 |
Eccentricity of orbit (semi-axis major = 1), | 0.0549080 |
Inclination of axis to ecliptic, | 1° 30′ 10″.8 |
Mean motion in a solar day, | 13° 10′ 35″ |
Maximum variation, | 35′ 42″ |
Maximum annual equation, | 11′ 11″.97 |
Maximum equation of centre, | 6° 17′ 12″ |
Horizontal parallax, maximum, | 1° 1′ 24″ |
Horizontal parallax mean, | 57′ 0″.9 |
Horizontal parallax minimum, | 53′ 48″ |
Volume (Earth's = 1), | 0.1364 |
Mass (Earth's = 1), | 0.1324 |
Density (Earth's = 1), | 0.972 |
Diameter (Earth's = 1), | 0.519 |
Diameter in miles, | 4070 |
Diameter, apparent, mean, | 5″.8 |
Diameter, apparent, minimum, | 3″.3 |
Diameter, apparent, maximum. | 23″-5 |
Gravity (Earth's = 1), | 0.49 |
In one second of time bodies fall, in feet, | 7.9 |
Time of rotation on axis, | 24h. 37m. 22s. |
Revolution, sidereal, in days, | 686.97945 |
Revolution, synodical. | 779.836 |
Light and heat from Sun (Earth's = 1), | 0.43 |
Polar less than equatorial diameter. | 1-16th |
Distance from the Sun, mean, in miles, | 145,750,000 |
Distance from the Sun, mean, (Earth's = 1), | 1.523691 |
Distance from the Sun,maximum, | 1.665779 |
Distance from the Sun,minimum. | 1.381602 |
Eccentricity of orbit (semi-axis major = 1) | 0.93258 |
Eccentricity of orbit, annual increase, | 0.00000090176 |
Longitude of perihelion, | 332° 23′ 56″.6 |
Longitude annual increase, | 15″-8 |
Longitude ascending node. | 48° 0′ 3″-5 |
Inclination of orbit to ecliptic, | 2″-8 |
Inclination of orbit to ecliptic, annual decrease. | 0″.014 |
Mean daily motion in orbit. | 31′ 26″-7 |
Inclination of axis to the ecliptic, | 59° 41′ 49″ |
Greatest arc of retrogradation, | 19° 35′ |
Edge of south polar spot from pole in winter, | 35° |
Edge of south polar spot from pole in summer. | 5° |
Brightness of polar spots (mean brightness = 1), | 2 |
Name. | Length of Sidereal Revolution in Days. | Inclination of Orbit to Ecliptic. | Discoverer. | Year of Discovery. | |||
° | ′ | ″ | |||||
1. | Ceres | 1681.271 | 10 | 36 | 30.9 | Piazzi | 1801 |
2. | Pallas | 1686.089 | 34 | 37 | 20 | Olbers | 1802 |
3. | Juno | 1592.736 | 13 | 3 | 17 | Harding | 1804 |
4. | Vesta | 1325.669 | 7 | 8 | 25 | Olbers | 1807 |
5. | Astrsea | 1511.369 | 5 | 19 | 23 | Hencke | 1845 |
6. | Hebe | 1379.635 | 14 | 46 | 32 | Hencke | 1847 |
7. | Iris | 1345.600 | 5 | 28 | 16 | Hind | 1847 |
8. | Flora | 1193.281 | 5 | 53 | 3 | Hind | 1847 |
9. | Metis | 1346.940 | 5 | 35 | 55 | Graham | 1848 |
10. | Hygeia | 2043.386 | 3 | 47 | 11 | De Gasparis | 1849 |
11. | Parthenope | 1399.074 | 4 | 36 | 54 | De Gasparis | 1850 |
12. | Victoria | 1303.255 | 8 | 23 | 7 | Hind | 1850 |
13. | Egeria | 1515.850 | 16 | 33 | 7 | De Gasparis | 1850 |
14. | Irene | 1515.373 | 9 | 5 | 33 | Hind | 1851 |
15. | Eunomia | 1576.493 | 11 | 43 | 50 | De Gasparis | 1851 |
16. | Psyche | 1834.658 | 3 | 3 | 37 | De Gasparis | 1852 |
17. | Thetis | 1441.859 | 5 | 35 | 39 | Luther | 1852 |
18. | Melpomene | 1270.498 | 10 | 10 | 38 | Hind | 1852 |
19. | Fortuna | 1397.192 | 1 | 33 | 18 | Hind | 1852 |
20. | Massilia | 1365.095 | 0 | 41 | 5 | De Gasparis | 1852 |
21. | Lutetia | 1542.318 | 3 | 5 | 6 | Goldschmidt | 1852 |
22. | Calliope | 1814.762 | 13 | 44 | 39 | Hind | 1852 |
23. | Thalia | 1554.131 | 10 | 13 | 59 | Hind | 1852 |
24. | Themis | 2051.993 | 0 | 49 | 24 | De Gasparis | 1853 |
25. | Phocea | 1350.281 | 21 | 42 | 30 | Chacornac | 1853 |
26. | Proserpine | 1580.714 | 5 | 0 | 26 | Luther | 1853 |
27. | Euterpe | 1332.301 | 1 | 39 | 42 | Hind | 1853 |
28. | Bellena | 1700.541 | 9 | 31 | 21 | Luther | 1854 |
29. | Amphitrite | 1499l.309 | 6 | 8 | 20 | Chacornac | 1854 |
30. | Urania | 1332.083 | 2 | 10 | 9 | Hind | 1854 |
31. | Euphrosene | 2083.297 | 26 | 53 | 26 | Fergusson | 1854 |
32. | Pomona | 1516.367 | 5 | 29 | 14 | Goldschmidt | 1854 |
33. | Polyhymnia | 1770.912 | 1 | 56 | 48 | Chacornac | 1854 |
34. | Circe | 1606.575 | 5 | 26 | 55 | Chacornac | 1855 |
35. | Leucothia | 1873.018 | 8 | 15 | 18 | Luther | 1855 |
36. | Atalanta | 1665.965 | 18 | 42 | 9 | Goldschmidt | 1855 |
37. | Fides | 1568.671 | 3 | 7 | 10 | Luther | 1855 |
38. | Leda | 1656.340 | 6 | 58 | 32 | Chacornac | 1856 |
39. | Lsetitia | 1683.348 | 10 | 20 | 51 | Chacornac | 1856 |
40. | Harmonia | 1246.846 | 4 | 15 | 48 | Goldschmidt | 1856 |
41. | Daphne | 1358.34 | 15 | 48 | 23 | Goldschmidt | 1856 |
42. | Isis | 1386.914 | 8 | 34 | 40 | Pogson | 1856 |
43. | Ariadne | 1191.108 | 3 | 20 | 0 | Pogson | 1857 |
44. | Nysa | 1599.700 | 3 | 53 | 0 | Goldschmidt | 1857 |
45. | Eugenia | 1617.641 | 6 | 35 | 0 | Goldschmidt | 1857 |
46. | Hestia | 1406.614 | 2 | 18 | 0 | Pogson | 1857 |
47. | Aglaia | 1793.933 | 5 | 6 | 0 | Luther | 1857 |
48. | Doris | 2000.220 | 6 | 30 | 0 | Goldschmidt | 1857 |
49. | Pales | 1980.255 | 3 | 8 | 0 | Goldschmidt | 1857 |
50. | Virginia | 1596.140 | 2 | 52 | 0 | Fergusson | 1857 |
51. | Nemausa | ... | 9 | 36 | 38 | Laurent | 1857 |
52. | Europa | ... | 7 | 24 | 41 | Goldschmidt | 1858 |
53. | Calypso | ... | 5 | 6 | 59 | Luther | 1858 |
54. | Alexandra | ... | 11 | 47 | 9 | Goldschmidt | 1858 |
55. | Pandora | ... | 7 | 13 | 30 | Searle | 1858 |
56. | Pseudo Daphne | ... | 7 | 56 | 2 | Schubert | 1858 |
57. | Mnemosyne | ... | 15 | 7 | 40 | Luther | 1859 |
58. | Concordia | ... | ... | Luther | 1860 | ||
59. | (Not named) | ... | ... | Chacornac | 1860 | ||
60. | Titania | ... | 4 | 40 | 18 | Fergusson | 1860 |
61. | Danae | ... | ... | Goldschmidt | 1860 | ||
62. | Erato | ... | 2 | 14 | 15 | Forsten | 1860 |
63. | Ansonia | ... | ... | De Gasparis | 1860 | ||
64. | Angelina | ... | ... | Tempel | 1861 | ||
65. | Maximiliana | ... | ... | Tempel | 1861 | ||
66. | Maia | ... | ... | Tuttle | 1861 | ||
67. | Asia | ... | ... | Pogson | 1861 | ||
68. | Leto | ... | ... | Luther | 1861 | ||
69. | Hesperia | ... | ... | Schiaparelli | 1861 | ||
70. | Ponopea | ... | ... | Goldschmidt | 1861 | ||
71. | Niobe | ... | ... | Luther | 1861 |
Aggregate mass (Earth's = 1), less than | 1-4th |
Inclination of orbit to ecliptic, greatest (Pallas), | 34° 37′ 20″ |
Inclination of orbit to ecliptic, least (Massilia), | 0° 41′ 5″ |
Distance from Sun (Earth's = 1), greatest (Euphrosene) | 3.192282 |
{{{1}}} least (Ariadne), | 2.19904 |
Distance, supposed planet, according to Bode's law, | 2.8 |
Pallas, diameter in miles, | 672 |
Pallas surface (Earth's =1), | 1-40th |
Pallas supposed density (Earth's = 1), | 1 |
Pallas gravity (Earth's =1), | 1-12th |
Pallas length of seconds' pendulum, in inches, | 3 |
Magnitudes through which some vary on successive nights, | 9-12th |
Supposed disrupted planet, according to Kirkwood's, law, diameter in miles, | 5000 |
Supposed disrupted planet, period of rotation, in hours, | 57.5 |
Volume (Earth's = 1), | 1491 |
Mass (Earth's = 1), | 338.718 |
Density (Earth's = 1), | .227 |
Diameter (Earth's = 1), | 11.225 |
Diameter in miles, | 92.164 |
Diameter apparent, mean, | 38″.4 |
Diameter apparent, minimum, | 30″ |
Diameter apparent, maximum, | 46″ |
Gravity (Earth's = 1), | 2.45 |
Gravity„ feet fallen in one second of time, | 39.4 |
Rotation on axis, | 9h. 55m. 50s. |
Light and heat from Sun at perihelion (Earth's = 1), | .0408 |
Light and heat from Sun at„ aphelion, | .0336 |
Light and heat from Sun at„ mean distance, | .0372 |
Polar less than equatorial diameter, | 1-20th |
Polar less than equatorial diameter, if planet were equally dense throughout, | 1-10th |
Magnifying power required to see the belts | 30 |
Magnifying power required to see the belts well, | 300 |
Greatest number of belts observed, | 40 |
Number of permanent belts, | 2 |
Time Cassini's spot was seen at intervals, in years, | 43 |
Proper motion in longitude, for one revolution, of some spots, | 3° |
Velocity of the wind from slower moving spots, feet in a second, | 350 |
Velocity of wind in greatest hurricane on the earth, feet in a second, | 50 |
Distance, east and west, of centre of disc beyond which spots are not usually visible, | 1h. 27m. |
Proportion of brightness at poles to that of the equator, | 1-2d |
Distance from the Sun, mean, in miles, (Earth's = 1), | 494,256,000 |
Distance from the Sun, maximum | 5.202767 |
Distance from the Sun, minimum, | 5.453663 |
Eccentricity of orbit (semi-axis major = 1), | 4.951871 |
Eccentricity of orbit annual increase. | .0482235 |
Longitude of perihelion, | .000001593 |
Longitude of perihelion, annual increase. | 11° 8′ 35″ |
Longitude of perihelion, ascending node, | 6″.96 |
Longitude of perihelion, annual decrease. | 98° 26′ 19″ |
Longitude of perihelion,|annual decrease, | 34″.3 |
Inclination of orbit to ecliptic, | 1° 18′ 51″ |
Inclination of orbit to ecliptic, annual decrease, | 0″-226 |
Motion, mean daily, | 4′ 59″ |
Motion, in 365 days, | 30° 20′ 32″ |
Inclination of axis to ecliptic. | 3° 5′ 30″ |
Mean arc of retrogradation. | 9° 54′ |
Revolution, sidereal, in mean solar days, | 4332.584821 |
Revolution, synodical, | 398.867 |
No. | Sidereal Revolution. |
Distance. Jupiter's radius = 1. |
Orbit inclined to Jupiter's equator. |
Diameter in miles. |
Mass. Jupiter =1 |
Apparent Diameter from Jupiter. | ||||||
d. | h. | m. | s. | ° | ′ | ″ | ′ | ″ | ||||
1 | 1 | 18 | 27 | 23 | 6.048 | 0 | 0 | 7 | 2436 | .000017 | 31 | 11 |
2 | 3 | 13 | 13 | 42 | 9.623 | 0 | 1 | 6 | 2187 | .000023 | 17 | 35 |
3 | 7 | 3 | 42 | 33 | 15.350 | 0 | 5 | 3 | 3573 | .000088 | 18 | 0 |
4 | 16 | 16 | 32 | 11 | 26.998 | 0 | 0 | 24 | 3057 | .000043 | 8 | 46 |
[1] (Mean longitude of the 1st + twice mean longitude of 3d) 3 times mean longitude of 2d is always = , |
180° |
- ↑ In consequence of this remarkable relation, the 1st, 2d, and 3d satellites can never be eclipsed all at once.
Volume (Earth's = 1), | 772 |
Mass (Earth's = 1), . | 101.364 |
Density (Earth's = 1), | .131 |
Diameter (Earth's = 1), | 9.022 |
Diameter in miles, | 75.070 |
Diameter apparent, mean, | 17″.1 |
Diameter apparent minimum. | 15″.0 |
Diameter apparent maximum. | 20″.0 |
Gravity (Earth's = 1), | 1.09 |
Gravity bodies fall in one second, in feet, | 17.6 |
Light and heat from Sun, perihelion (Earth's = 1) | .0123 |
Light and heat from Sun aphelion, | .0099 |
Light and heat from Sun mean, | .0111 |
Polar less than equatorial diameter. | 1-10th |
Distance from the Sun, mean, in miles, | 906,205,000 |
Distance from the Sun, (Earth's = 1), | 9,538,850 |
Distance from the Sun, in miles, maximum, | 10,073,270 |
Distance from the Sun, in miles, minimum, | 9,004,422 |
Eccentricity of orbit (semi-axis major = 1), | .0560265 |
Eccentricity of orbit, annual decrease, | .0312402 |
Longitude of perihelion, | 89° 9′ 29″.8 |
Longitude of perihelion, annual increase, | 19″.4 |
Longitude„ ascending node, | 111° 56′ 37″.4 |
Longitude„ ascending node, annual decrease, | 19″.4 |
Inclination of orbit to ecliptic, | 2° 29′ 35″.7 |
Inclination of orbit to ecliptic, annual decrease, | 0″.155 |
Motion, mean daily, | 2′ 0″.6 |
Motion, in 365 days, | 12°13′36″.08 |
Inclination of axis to ecliptic, | 31° 19′.0 |
Rotation on axis, | 18h. 29m. 17s. |
Revolution, sidereal, in days, | 10759.2197106 |
Revolution, synodical, | 378.090 |
Mean arc of retrogradation, | 6° 44′ |
Bright ring, exterior diameter in miles, | 176,418 |
Bright ring, breadth of exterior division, | 10,573 |
Bright ring, interval between the two divisions, | 1,791 |
Bright ring, exterior diameter of interior division, | 151,690 |
Bright ring, breadth of interior division, | 17,175 |
Bright ring, time of rotation, | 10h, 35m. 15s. |
Dusky ring, breadth, | 6,350 |
Dusky ring„ interval between inner edge and Saturn, | 7,460 |
Divisions, seen by Bond, | 2 |
Divisions discovered by Bond in the year | 1850 |
Years in which it will reach the planet by increase of breadth of system of rings (O. Striive), | 125 |
Breadth of whole system of rings, | 35,889 |
Exterior division of bright ring, exterior diameter, | 40″.44 |
Exterior division new sub-division, exterior diameter (Encke), | 37″.47 |
Exterior division new sub-division, interior diameter, | 36″.04 |
Divisions of exterior bright ring, seen by Kater, | 4 |
Divisions in inner bright ring, seen by De Vico, | 2 |
Divisions in inner bright ring, seen by Dawes, | 4 |
Isolated stationary bright spots on disappearance of rings, at least | 4 |
No. | Name. | Sidereal Revolution. |
Distance. Saturn's radius = 1. |
Discoverer. | Year of Discovery. | |||
d. | h. | m. | s. | |||||
1 | Mimas | 0 | 22 | 36 | 18 | 3.1408 | Herschel | 1789 |
2 | Enceladus | 0 | 8 | 53 | 3 | 4.0319 | Herschel | 1789 |
3 | Tethys | 1 | 21 | 18 | 33 | 4.9926 | Cassini | 1684 |
4 | Dione | 2 | 17 | 44 | 51 | 6.399 | Cassini | 1684 |
5 | Rhea | 4 | 12 | 25 | 11 | 8.932 | Cassini | 1672 |
6 | Titan | 15 | 22 | 41 | 25 | 20.706 | Huyghens | 1655 |
7 | Hyperion | 21 | 4 | 20 | 0 | 25.029 | Bond & Lassell | 1848 |
8 | Japetus | 79 | 7 | 54 | 41 | 64.359 | Cassini | 1671 |
Hyperion discovered by Bond and Lassell on same night, year | 1848 |
Greatest inclination to the plane of the ring
(Japetus), |
12° 14′ |
Apparent diameter of the largest. Titan, (diam. of Saturn = 1), | 1-10th |
Length of telescope with which Huyghens discovered Titan, in feet, | 124 |
Length of telescope with which Cassini discovered
Tethys and Dione, in feet, |
145 |
Volume (Earth's = 1) | 86.5 |
Mass (Earth's = 1), | 14.251 |
Density (Earth's = 1), | .167 |
Diameter (Earth's = 1), | 4.575 |
Diameter in miles . | 36,216 |
Diameter apparent, mean, | 4″.1 |
Gravity (Earth's = 1), | 0.76 |
Gravity bodies fall in one second of time, in feet, | 12.3 |
Light and heat from Sun, perihelion, | .0027 |
Light and heat from Sun, aphelion. | .0025 |
Polar less than equatorial diameter, | 1-9th |
Observed by Flamstead in | 1690 |
Discovered by Herschel in | 1781 |
Magnitude of Uranus as a star (occasionally seen with naked eye), | 6th |
Distance from the Sun, mean, in miles, | 1,822,328,000 |
Distance from the Sun, mean, (Earth's = 1), | 19.18239 |
Distance from the Sun, mean, in miles, maximum | 20.07630 |
Distance from the Sun, mean, in miles, minimum, | 18.28848 |
Eccentricity of orbit (semi-axis major =1), | 0.04667938 |
Longitude of perihelion, | 167° 31′ 16″.1 |
Longitude of perhilion, annual increase | 2″.28 |
Longitude of ascending node, | 72° 59′ 35″ |
Longitude of ascending node, annual decrease, | 36″.05 |
Inclination of orbit to ecliptic. | 46′ 28″.44 |
Incilination of orbit to ecliptic, annual increase, | 0.03 |
Motion, mean daily, | 42″.35 |
Motion, in 365 days. | 4° 17′ 45″ |
Inclination of axis to ecliptic, | unknown |
Rotation on axis, | unknown |
Revolution, sidereal, in days, | 30686.820829 |
Revolution. synodical, | 369.656 |
Mean arc of retrogradation, | 3°.36 |
No. | Name. | Sidereal Revolution. |
Mean Apparent Distance. |
Discoverer, | Year of Discovery. | |||
d. | h. | m. | s. | ″ | ||||
1 | Ariel | 2 | 12 | 29 | 21 | 13.54 | Lassell | 1851 |
2 | Umbriel | 4 | 3 | 28 | 8 | 19.28 | Lassell | 1851 |
3 | Titania | 8 | 16 | 56 | 31 | 31.44 | Herschel | 1787 |
4 | Oberon | 13 | 11 | 7 | 13 | 42.87 | Herschel | 1787 |
Additional satellites seen by Herschel, but not re-observed, | 4 |
Direction of movement of satellites | retrograde |
Inclination of the orbits of Titania and Oberon to ecliptic, | 78° 58′ |
Distance from the planet -when satellites become invisible (Herschel), | 14″ |
IMagnifying power required for sustained view, | 300 |
Volume (Earth's = 1), | 76.6 |
Mass (Earth's = 1), . | 18.900 |
Density (Earth's = 1), | .321 |
Diameter (Earth's = 1), | 4.246 |
Diameter in miles, | 33,610 |
Diameterapparent, mean, | 2.″4 |
Gravity (Earth = 1), | 1.36 |
Gravity bodies fall in one second, in feet, | 21.8 |
Light and heat from Sun, perihelion, | .0011 |
Light and heat from Sun, aphelion, | .0011 |
Year in which Adams computed its place within 2 degrees, | 1845 |
Year in which Leverrier computed its place, | 1846 |
First observed by M. Galle, from Leverrier's indications, 23d Sept., | 1846 |
Observed by M. Challis, but not recognised, from Adams' indications, 4th Aug., | 1846 |
Observed as a fixed star by Lalande in | 1795 |
Magnitude as a star, | 7-8th |
Disc seen with a magnifying power of | 150 |
Distance from the Sun, mean in miles, | 2,853,420,000 |
Distance from the Sun, mean (Earth's = 1), | 30.03627 |
Distance from the Sun, mean in miles, maximum, | 30.29816 |
Distance from the Sun, mean in miles, minimum, | 29.77438 |
Eccentricity of orbit (semi-axis major = 1), | .0087193 |
Longitude of perihehon, epoch 1854, | 47° 17′ 58″ |
Longitude of ascending node. | 130° 10′ 12″ |
Inclination of orbit. | 1° 46′ 59″ |
Motion, mean daily, | 21″.6 |
Motion in 365 days, | 2° 11′ 24″ |
Inclination of axis to ecliptic, | unknown |
Rotation on axis. | unknown |
Revolution, sidereal, in days, | 60126.722 |
Revoulution„ synodical, | 367.488 |
Sidereal revolution, | 5d. 24h. 0m. 17s. |
Sidereal mean distance, apparent, | 16″.75 |
Sidereal mean distance, in miles, | 232,000 |
Orbit inclined to plane of ecliptic. | 29° |
Longitude of the ascending node. | 175° 40′ |
Halley's—Time of perihelion passage, 15th Nov. 1835, | 22h. 41m. 22s. |
Halley's longitude of perihelion, | 304° 31′ 32″ |
Halley's longitude of ascending node, | 55° 9′ 59″ |
Halley's inclination of orbit to ecliptic, | 17° 45′ 5″ |
Halley's—Eccentricity, | 0.967391 |
Halley's semi-axis, | 17.98796 |
Halley's period in days, motion retrograde, | 27865.74 |
Encke's—Time of perihelion passage, 9th Aug. 1845, | 15h. 11m. 11s. |
Encke's longitude of perihelion, | 157° 44′ 21″ |
Encke's longtitude ascending node, | 334° 10′ 33″ |
Encke's inclination to the ecliptic, | 13° 7′ 34″ |
Encke's semi-axis, | 2.21640 |
Encke's eccentricity, | 0.847436 |
Encke's period, motion direct, | 1203d.23 |
Biela's — Time of perihelion passage, 11th Feb. 1846, | 0h. 2m. 50s. |
Biela's longitude of perihelion, | 109° 5′ 47″ |
Biela's longitude of ascending node, | 245° 56′ 58″ |
Biela'sinclination to the ecliptic, | 12° 34′ 14″ |
Biela's semi-axis, | 3.50182 |
Biela's eccentricity, | 0.755471 |
Biela's period, motion direct, | 2393d..52 |
Faye's—Time of perihelion passage, 17th Oct. 1843, | 3h. 42m. 16s. |
Faye's longitude of perihelion, | 49° 34′ 19″ |
Faye's longitude ascending node, | 209° 29′ 19″ |
Faye's inclination to ecliptic, | 11° 22′ 31″ |
Faye's semi-axis, | 3.81179 |
Faye's eccentricity, | 0.555962 |
Faye's period, motion direct, | 2718″ 26 |
DeVico's—Time of passing perihelion, 2d Sept. 1844, | 11h. 36m. 53s. |
DeVico's longitude of perihelion, | 342° 31' 15" |
DeVico's longitude ascending node, | 63° 49' 31" |
DeVico's inclination to ecliptic, | 2° 54' 45" |
DeVico's semi-axis, | 3.09946 |
DeVico's eccentricity, | 0.617256 |
DeVico's Period, motion direct, | 1993d.09 |
Brorsen's—Time of passing perihelion, 25th Feb. 1846, | 9h. 13m. 35s. |
Brorsen's longitude of perihelion, | 116° 28′ 34″ |
Brorsen's longitude of ascending node, | 102° 39‘ 36″ |
Brorsen's inclination to ecliptic, | 30° 55′ 7″ |
Brorsen's semi-axis, | 3.15021 |
Brorsen's—Eccentricity, | 0.793629 |
Brorsen's period, motion direct, | 2042 d.24 |
Number of calculated non-periodic comets up to end of 1855, | 206 |
Number with short periods, | 12 |
Number with medium periods (Halley's included), | 5 |
Number with long periods, probably | 10 |
Number moving in hyperbolas, | 3 |
Number of comets observed down to 1850, | 607 |
Number to which periods have, with probability, been assigned, about | 30 |
Probable number of comets, supposing perihelia equally distributed within the sphere of the orbit of Neptune, | 17,558,424 |
Biela's comet separated into two on 13th January | 1846 |
Biela's comet interval between the two parts on 5th March, | 9′ 19″ |
Biela's comet earth escaped collision in 1832 by | 30d. |
Biela's comet on return in 1852, the two parts were separated, in miles | 1,250,000 |
Length of tail of great comet of 1680 in miles, | 140,000,000 |
Length of tail of great comet of 1680 in arc, | 90° |
Time in which tail was developed, in days, | 2 |
Number of tails of comet of 1744, | 6 |
Maximum limit of density of Donati's comet, | 0.00000017 |
Arc described by comet of 1472 in a day, | 40° |
Comet of 1680, distance from Sun at perihelion (Sun's diameter = 1), | 1-6th |
Comet of 1680, heat, according to Newton (red hot iron = 1), | 2000 |
Comet of 1680, heat, according to Newton, time required to lose it, in years, | 50,000 |
Halley predicted the return of the comet of 1531 and 1607 in | 1759 |
Halley's comet, maximum length of tail, 15th Oct., 1835, | 20° |
Halley's comet, length on 5th Nov. 1835 (perihelion 15th Nov.), | 2° 30′ |
Halley's comet, jet and tail commenced | Oct. 2 |
Halley's comet, oscillation of jet obvious in the course of | 1h. |
Halley's comet, invisible after the perihelion, in months, | 2 |
Halley's comet, diameter of disc when seen, not including coma, | 2′ |
Halley's comet, increase of volume of illuminated space during six days, from Jan. 25, | 40 times |
Return of Charles V. comet of 1556, predicted by Hind in period | 1856-61 |
Period of Encke's comet, shortening at the rate, per revolution, of | Od..11 |
Lexell's comet of 1770, period in years, | 5.5 |
Lexell's comet of 1770, thrown out of the system by attraction of Jupiter in | 1779 |
Lexell's comet of 1770, distance from Sun at perihelion (Sun's radius = 1), | 1-7th |
Lexell's comet of 1770, angular diameter of Sun at perihelion, | 121° 32" |
Lexell's comet of 1770, disc of Sun at perihelion (disc from Earth = 1), | 47,000 |
Lexell's comet of 1770, heat at perihelion (heat of 32 inch burning lens = 1), | 25 |
Lexell's comet of 1770, velocity at perihelion, miles, in one second, | 366 |
Lexell's comet of 1770, tail stretching to the Earth's orbit, whirled round in two hours, | 180° |
Lexell's comet of 1770, radius of head on 29th March, in miles, | 47,000 |
Lexell's comet of 1770, length of tail, | 150,000,000 |
Lexell's comet of 1770, breadth of tail, | 3,000,000 |
Periodic comets, all direct when inclination under | 17° |
Comets calculated before 1849, direct, | 94 |
Comets calculated before 1849, retrograde, | 100 |
Great comet of 1861, distance from the Earth on June 30, . | 17,000,000 |
Great comet of 1861, surmised by Hind that the Earth passed through its tail, | 30th June |
Great comet of 1861, length of tail as seen at Rome | 118° |
Great comet of 1861, length of tail as seen at Paris | 45° |
Great comet of 1861, polarisation of tail strong, but no trace in nucleus till | 3d July |
Great comet of 1861, tail seen to flicker and disappear for an instant. | 4th July |
Encke's comet, before perihelion, diameter diminished in two months to | 1-90th |
Encke's comet after perihelion, diameter increased in six days from 1 to . | 40 |
Rotation of comet of 1825 (doubtful), | 19h. 37m. |
Mass of Lexell's comet less than (Earth's = 1) | 1-5000th |
Chances unfavourable to collision between earth and a comet (comet's diam. = l-4th of earth's), | 281,000,000 |
Number of binary systems with assigned periods, about | 15 |
Period of Castor, with semi-axis of 8", in years, | 252 |
Period of χ Ursro Majoris, with semi-axis of 3″.8 | 59 |
Period of γ Virginis, with semi-axis of 3″.6, | 182 |
Causes of colour in stars, intrinsic and complementary, | 2 |
Number of stars covered by the Moon in parts of the Milky Way, | 2000 |
Number of stars in some clusters, | 50, |
Number of typical forms of nebulæ (globular and spiral), | 2 |
Hour of ascension richest in nebulæ, | 12 |
Nebula in Andromeda, largest elliptical nebula visible to naked eye. | |
Nebula in Andromeda,„ dark streaks running parallel to longer axis, | 2 |
Largest annular nebula in Lyra. | |
Planetary nebulæ, number of, about | 25 |
Planetary nebulæ, largest, distance from β Ursæ Majoris, | 12′ |
Planetary nebulæ, largest, apparent diameter, | 2′ 40″ |
Light of nebula of 1' diameter if as bright as the Sun, in full Moons, | 780 |
Double nebulæ, probable physical connexion as in double stars. | |
Most brilliant nebulous star in Andromeda, No. | 65 |
Regions of amorphous nebulse — Orion, Argo, Saggitarius, Cygnus, | 4 |
Nebula in sword-handle of Orion, discovered by Huyghens in | 1656 |
Nebula in sword-handle of Orion, diameter, horizontal, | 30′ |
Nebula in sword-handle of Orion, diameter,vertical, | 24′ |
Variable nebula, | 1 |
Zodiacal light, maximum distance of vertex from Sun, | 90° |
Zodiacal light, maximum breadth at base, | 30° |
November meteors, passing through γ Leonis, period, | 12th-14th |
Number of zones of asteroids, | 3 |
Magnitude of the smallest stars visible, | 7th |
Magnitude of the stars visible by the most powerful telescopes, | 16th |
Light of a star of the 6th magnitude (1st magnitude = 1), | 1-1OOth |
Number of stars of 1st magnitude, | 24 |
Number of stars of 1st magnitude, 2d magnitude, | 50-60 |
Number of stars of 1st magnitude, 3d magnitude, | 200 |
Number of stars total registered to 7th magnitude, about | 15,000 |
Number of stars total visible in Herschel's 20-feet telescope, | 5,500,000 |
Rate at which light travels per second, in miles, | 200,000 |
Time required by light to traverse the distance of a star with one second of parallax, in years, | 3y. 83d. |
Corresponding distance in billions of miles, | 20 |
Distance of smallest stars seen in telescopes of 75 space penetrating power, measured by light in years, | 2,000 |
Star 61 Cygni, parallax first detected in it, by Bessel, | 0″.349 |
Star 61 Cygni, proper motion annually, | 5″ |
Star 61 Cygni, distance of component stars, | 15″ |
Star 61 Cygni, sum of masses of the component stars (Sun = 1), | 0.353 |
α Centauri, parallax, | 0″.9128 |
α Centauri, nearest star, distance measured by light, in years, about | 3.5 |
α Centauri, proper motion, | 4″ |
Number of stars to which parallax has been assigned, | 9 |
Probable average distance of stars of 1st magnitude, measured by light, in years, | 15.5 |
Probable average distance of stars of 2d magnitude, | 28 |
Probable average distance of stars of 3d magnitude, | 43 |
Probable average distance of stars of 4th magnitude, | 60 |
Probable average distance of stars of 5th magnitude, | 84 |
Probable average distance of stars of 6th magnitude, | 120 |
Nebulæ, proportion of sphere containing one-third of whole mass, near north pole of the galaxy, | 1-8th |
Largest proper motion, 1830, Groombridge, | 7″ |
Diameter of the Sun removed to a distance corresponding to one-second parallax, | 0″.0093 |
Light of Sirius (Sun's = 1 at the same distance), | 63 |
Light of the Sun (Sirius = 1) at the Earth, | 20,000,000,000 |
Variable star Algole, period, | 2d 20h 48m |
Variable star Algole, variation in magnitude, | 2.4 |
Variable star δ Cephei, period, | 5d 8h 47m |
Variable star δ Cephei, variation in magnitude, | 3.5 |
Variable star β Lyræ., period, | 12d 23h 53m |
Variable star, β Lyræ. variation in magnitude, | 3.4 |
Number of variable stars, with assigned periods, about | 6O |
Double stars, odds against one chance combination of 4″ closeness, | 9570 to 1 |
Double stars, number of such combinations, upwards of | 100 |
Sun's distance from Alcyone, the centre of the stellar system (Mædlar), (radius of Earth's orbit = 1), | 34,000,000 |
Sun's time of revolution round Alcyone, in years, | 19,256,000 |
Sun's velocity in space (Earth's annual motion = 1), | 1.4 |
Sun, point in Hercules, to which it is moving, | |
Sun, point in Hercules, north declination, | 34° 37′ |
Sun, point in Hercules, right ascension, | 259°'90 |
Lord Rosse's Great Reflector, diameter of mirror, in feet, | 6 |
Lord Rosse's Great Reflector, thickness of mirror, in inches, | 5 |
Lord Rosse's Great Reflector, focal length, in feet, | 54 |
Lord Rosse's Great Reflector length of tube, in feet, | 56 |
Lord Rosse's Great Reflector diameter of tube, in feet, | 7 |
Lord Rosse's Great Reflector. weight of speculum, in tons, | 3 |
Lord Rosse's Great Reflector. expense, | £12,000 |
Cambridge, U.S., refractor, diameter of object glass, in inches, | 15.125 |
Cambridge, U.S., refractor, length of tube, in feet, | 23 |
Cambridge, U.S., refractor, magnifying powers, | 180-2000 |
Cambridge, U.S., refractor, weight in tons, | 3 |
Cambridge, U.S., refractor, diameter of declination-circle, in inches, | 26 |
Cambridge, U.S., refractor, diameter of hour circle, | 18 |
Cambridge, U.S., refractor, cost, | £4,000 |
Object-glass by Clarke, diameter, in inches, | 18.5 |
Object-glass by Clarke, diameter, contract price, | £2237 |
Diameter of object-glass in process of execution by Cooke, in inches, | 24 |
THE END