Astrophysics (Index)About

astronomical unit

(AU)
(about 93 million miles)

An astronomical unit (AU) is a distance unit intended to convey the distance between the Earth and the Sun, or more specifically the mean of the Earth's orbit's aphelion and perihelion. However, it is now fixed at 149597870700 meters, considered a reasonable exact unit to approximate the Earth-Sun distance. It is commonly used for distances within the solar system and other star systems, e.g., for orbital radii. An AU is:

Some distances in AU:

0.0026 AU distance from Earth to Moon
0.0093 AU diameter of the Sun
5.2 AU radius of Jupiter's orbit
30 AU radius of Neptune's orbit
276200 AU distance to Alpha Centauri
1.6 billion AU distance to galactic center
1604 billion AU distance to Andromeda

(distance,unit,Earth,Sun,astronomy)
Further reading:
https://en.wikipedia.org/wiki/Astronomical_unit

Referenced by pages:
Achernar
astronomical quantities
Avogadro's number (NA)
Beta Centauri
Beta Pictoris b (β Pic b)
Ceres
10199 Chariklo
direct imaging
Earth
evaporating gas globule (EGG)
escape velocity (Ve)
extra-solar planet
51 Eridani b
51 Pegasi b (51 Peg b)
giant star
GJ 1132 b
Gliese 436 b (GJ 436 b)
Haumea
HD 189733 b
HD 209458 b
HD 80606 b
heliopause
heliosheath
heliosphere
Hills Cloud
hot Jupiter (HJ)
HR 8799
J1407
Jupiter
K2-18b
Kepler-16b
Kepler-452b
Kepler-79
Kuiper Belt (K Belt)
LHS 3844 b
light-year (ly)
Mars
Mercury
mole (mol)
Neptune
occultation observations
Oort Cloud
parallax
Parker Solar Probe (PSP)
parsec (pc)
Planet Nine
planetary migration
Pluto
Poynting-Robertson effect
protoplanetary disk (PPD)
radial velocity (RV)
red giant
Rigel
Saturn
Scholz's Star
Schwarzschild radius (RS)
Sedna
Comet Shoemaker-Levy 9
67P/Churyumov-Gerasimenko (67P)
snow line
solar constant
Spitzer Space Telescope (SST)
supergiant
trans-Neptunian object (TNO)
TOI 700 d
2010 TK7
Ulysses
Uranus
Venus
Voyager
WASP-33b
WASP-43b
WASP-67b
wide binaries (WB)

Index