| Constant |
Symbol |
Systema |
Valueb |
| Equatorial radius of Earth
| a
| C
| 6,378,388 m
|
|
|
| Rc
| 6,378,160 m
|
| Flattening of Earth
| f
| C
| 1/297
|
|
|
| R
| 1/298.25 = 0.0033529
|
| Polar radius of Earth
| a(1 - f)
| C
| 6,356,911.946 m
|
| Normal gravity
| g
| C
| 978.049(1 + 0.0052884 sin2φ - 0.0000059 sin22φ) cm/sec2
|
| Solar parallax
| π
| C
| 8".80
|
|
|
| R
| 8".79405 or 8".794d
|
| Constant of nutation, 1900.0
| N
| C
| 9".21
|
|
|
| Rc
| 9".210
|
| Constant of aberration
| k
| C
| 20".47
|
|
|
| R
| 20".4958
|
| General precession in longitude per tropical century
| p
| C
| 5025".64 + 2".22T
|
|
|
| Rc
| 5025".64
|
| Precession in right ascension per tropical century
| m
| C
| 4608".50 + 2".79T
|
| Precession in declination per tropical century
| n
| C
| 2004".68 - 0".85T
|
| Speed of rotation of the ecliptic per tropical century
| π
| C
| 47".11 - 0.07T
|
| Longitude of axis of rotation of the ecliptic
| Π
| C
| 173°57'03".6 + 3286".2T
|
| Obliquity of the ecliptic
| ε
| C
| 23°27'08".26 - 46".845T - 0".0059T2 + 0".0081T3
|
| Equatorial horizontal parallax of the Moon at distance 60.2665 equatorial radii of thehh Earth
|
| C
| 57'02".70
|
| Velocity of light
| c
| C
| 299,860 km/sec = 186,324 statute miles/sec
|
|
|
| Rc
| 299,792.5 km/sec
|
| Time required for light to travel unit distance
|
|
|
|
| -Calculated from solar parallax
|
| C
| 498".580
|
| -Calculated from constant of aberration
|
| C
| 498".38
|
| Gaussian constant of gravitation
| k
| C
| 0.017202098950000 = 3548".18760069651
|
|
|
| Rc
| 0.01720209893
|
| Number of ephemeris seconds in 1 tropical year (1900)
|
| Rc
| 31,556,925.9747
|
| Measure of 1 AU
| A
| Rc
| 149,600 X 106
|
| Dynamical form factor for Earth
| J2
| Rc
| 0.0010827
|
| Geocentric gravitational constant
| GE
| Rc
| 398,603 X 109 m3/sec2
|
| Sidereal mean motion of Moon (1900)
| nc*
| Rc
| 2.661699489 X 10-6 radius/sec
| |
| Heliocentric gravitational constant, A3k'2
| GS
| R
| 132,718 X 1018 m3/sec2
|
| Perturbed mean distance of Moon, F2 [GE(1 + μ)/nc*2]1/3
| ac
| R
| 384,400 X 103 m
|
| Constant of sine parallax for Mooon, ae/ac
| L
| R
| 6".43987 or 6".440c
|
| Constant for parallactic inequality, F2[(1 - μ)/(1 + μ)](ac/A)
| Pc
| R
| 124".986
|
| Planetary mass ratios
|
|
|
|
| -Earth to Moon
|
| C
| 81.45 (for lunar inequality) and 81.53 (by Brown's theory)
|
| -Sun to
|
|
|
|
| --Earth plus Moon
|
| C
| 329,390
|
|
|
| R
| 328,912
|
| --Earth
|
| R
| 332,958
|
| --Mercury
|
| R
| 6,000,000
|
| --Venus
|
| R
| 408,000
|
| --Mars
|
| R
| 3,093,500
|
| --Jupiter
|
| R
| 1,047.355
|
| --Saturn
|
| R
| 3,501.6
|
| --Uranus
|
| R
| 22,869
|
| --Neptune
|
| R
| 19,314
|
| --Pluto
|
| R
| 360,000
|