Below are the CBEs as determined by the NSFA WG. This is a work in progress and the constants in the list and their associated values are subject to (possibly frequent) change. The values will not be considered final until the 2009 IAU General Assembly makes a decision concerning these values.
The items in blue are new from the previous IAU list of current best estimates. Unless otherwise noted, the constants should be considered to be in terms of the Système International d'Unités (SI). [Work in Progress]
Constant | Description | Value | Reference | Adopted |
---|---|---|---|---|
Natural Defining Constants | ||||
c | Speed of light | 2.997 924 58 x 108 ms-1 | [7] | IAU, IERS |
Auxiliary Defining Constants | ||||
k[1] | Gaussian gravitational constant | 1.720 209 895 x 10-2 | [14, 11] | IAU |
LG | 1-d(TT)/d(TCG) | 6.969 290 134 x 10-10 | [15, 25] | IAU, IERS |
LB | 1-d(TDB)/d(TCB) | 1.550 519 768 x 10-8 | [16] | IAU |
TDB0[2] | TDB - TCB at T0 | -6.55 x 10-5 s | [16] | IAU |
θ0[3] | Earth Rotation Angle at J2000.0 | 0.779 057 273 264 0 revolutions | [15, 4] | IAU |
dθ/dt[3] | Rate of advance of Earth Rotation Angle | 1.002 737 811 911 354 48 revolutions UT1-day-1 | [15, 4] | IAU |
Constant | Description | Value | Uncertainty | Reference | Adopted |
---|---|---|---|---|---|
Natural Measurable Constants | |||||
G | Constant of gravitation | 6.674 28 x 10-11 m3kg-1s-2 | 6.7 x 10-15 m3kg-1s-2 | [7] | |
Derived Constants | |||||
au[4] | Astronomical unit | 1.495 978 707 00 x 1011 m | 3 m | [26] | |
LC | Average value of 1-d(TCG)/d(TCB) | 1.480 826 867 41 x 10-8 | 2 x 10-17 | [18] | IAU, IERS |
Body Constants[5] | |||||
MM/ME | Ratio of the mass of the Moon to the Earth | 1.230 003 71 x 10-2 | 4 x 10-10 | [26] | |
MS/MMe | Ratio of the mass of the Sun to Mercury | 6.023 6 x 106 | 3 x 102 | [1] | IERS |
MS/MV | Ratio of the mass of the Sun to Venus | 4.085 237 19 x 105 | 8 x 10-3 | [23] | |
MS/MMa | Ratio of the mass of the Sun to Mars | 3.098 703 59 x 106 | 2 x 10-2 | [24] | |
MS/MJ | Ratio of the mass of the Sun to Jupiter | 1.047 348 644 x 103 | 1.7 x 10-5 | [20] | |
MS/MSa | Ratio of the mass of the Sun to Saturn | 3.497 901 8 x 103 | 1 x 10-4 | [21] | |
MS/MU | Ratio of the mass of the Sun to Uranus | 2.290 298 x 104 | 3 x 10-2 | [19] | IERS |
MS/MN | Ratio of the mass of the Sun to Neptune | 1.941 226 x 104 | 3 x 10-2 | [22] | |
MS/MP | Ratio of the mass of the Sun to Pluto | 1.365 66 x 108 | 2.8 x 104 | [29] | |
MS/MEris | Ratio of the mass of the Sun to Eris | 1.191 x 108 | 1.4 x 106 | [2] | |
MCeres/MS | Ratio of the mass of Ceres to the Sun | 4.72 x 10-10 | 3 x 10-12 | [26] | |
MPallas/MS | Ratio of the mass of Pallas to the Sun | 1.03 x 10-10 | 3 x 10-12 | [26] | |
MVesta/MS | Ratio of the mass of Vesta to the Sun | 1.35 x 10-10 | 3 x 10-12 | [26] | |
aE[6] | Equatorial radius of the Earth | 6.378 136 6 x 106 m | 1 x 10-1 m | [12, 3] | IERS |
J2[6] | Dynamical form factor | 1.082 635 9 x 10-3 | 1 x 10-10 | [12] | IERS |
dJ2/dt | Long-term variation in J2 | -3.001 x 10-9 cy-1 | 6 x 10-10 cy-1 | [16] | |
GMS | Heliocentric gravitational constant | 1.327 124 420 99 x 1020 m3s-2 (TCB-compatible) 1.327 124 400 41 x 1020 m3s-2 (TDB-compatible) |
1.0 x 1010 m3s-2 (TCB-compatible) 1.0 x 1010 m3s-2 (TDB-compatible) |
[8] | |
GME | Geocentric gravitational constant | 3.986 004 418 x 1014 m3s-2 (TCB-compatible) 3.986 004 415 x 1014 m3s-2 (TT-compatible) 3.986 004 356 x 1014 m3s-2 (TDB-compatible) |
8 x 105 m3s-2 (TCB-compatible) 8 x 105 m3s-2 (TT-compatible) 8 x 105 m3s-2 (TDB-compatible) |
[27] | IERS |
W0 | Potential of the geoid | 6.263 685 60 x 107 m2s-2 | 5 x 10-1 m2s-2 | [12] | IERS |
ω[7] | Nominal mean angular velocity of the Earth | 7.292 115 x 10-5 rad s-1 | [12] | IERS | |
Initial Values at J2000.0 | |||||
εJ2000[8] | Obliquity of the ecliptic at J2000.0 | 8.438 140 6 x 104 " | 1 x 10-3 " | [16, 13, 6] | IAU |
Last updated 10 August 2009.